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Full text of "Sync Magazine Volume 3 Number 4"

The magazine for Sinclair users and TIMEX /Sinclair users 




July/August 1983 
Volume 3, Number 4 



$2.95 



BUYER'S GUIDE: PART II 

SYNC AT THE WORKBENCH: Robotics on a Budget • Build a "TS 2000' 

Connect a Monitor • Add a Counter • Add a Joystick • Hardware Tips 

MACHINE LANGUAGE: MC and your TV Screen • REVIEWS: Votem 




SP€ND 
MOR€TIM€ 

UIITHVOUR 

TIM€X 



Action-pocked ncui computer gomes. Time saving 
home ond business software. Add-ons to moke your 
Timex more versatile ond powerful than ever before. 
These ore just o few of the reasons you'll be spending 
o lot more tim-j with your Timex once you discover 
Do to -Rssette — products developed specifically for 
your Timex Sinclair Computer. 

ADD-ONS 



Here are the accessories that will make your Timex as powerful 
and versatile as computers costing lots more. Expand 
your memory. Simplify loading and copying. All without break- 
ing your buaget. 



> ZX-99 TAPE CONTROL UNIT 

Advanced data processing features at a 
fraction of the cost. Mass storage. Save, 
load, and merge files. Interface with 
any serial printer. Automatically control 
up to four cassette decks. Price: $99.95. 



• PERFORMANCE IMPROVEMENT SYS- 
TEM No more tape headaches. Sets record and 
playback levels precisely. Checks head alignment. 
Includes an in-depth book on the use of cassette 
recorders with microcomputers. Price: $29.95. 



SOFTWMK 



K 





AEKM)N MEMORY 



T1MEX-SINCLAIR 



• RAM EXPANSION PACKS The fastest, least 
expensive way to add powerful memory expan- 
sion to your Timex. Designed so they won't 
shake loose. 16K Unit: $39.95 32K Unit: $89.95 
64K Unit: $149.95 



• POWER SUPPLY Foil that flicker and fade. A full one amp 
will support a host of peripherals. And a convenient on/off 
switch for easy power-up/power-down. Price: $1 9.95 



GAM€S 

(RCQUIR6 16K) 

• Great Western Hit 

the trail to adventure as 
you make the decisions 
that will spell survival or 
disaster in the great 
outdoors. Price: $19.95 

• Time Trippers 
Take a trip through 
history as you work to 

latch time-bending 

oles that riddle the 
universe. Arcade adven- 
ture at its best. Price: 
$19.95 

• Gobble A fast-moving maze game that simulates the origi- 
nal. Players can advance to ten different levels of difficulty for a 
real challenge. Price: $19.95 

€NJOVflBL€ l€RRNING 

• Micro Music (requires 32K) Converts your computer key- 
board into a musical one generating 43 musical tones (37. 
octaves) that can be heard through headphones or your 
cassette player. Price: $9.95 

• ZX Compiler Convert your ZX-8 1 /TS-1 000 BASIC pro- 
grams to machine language. Increases execution speed and 
teaches you the nuances of compiled programs. Price: $24.95 

flsk for Data- Assette software ond add-ons ot your 
computer dealer. For further information, call Data- 
Assette (1 800 932 4807) or send $2.50 (creditoble 
toward purchase) for o complete catalog of Data 
Assette products. And plan on spending alot more 
time with your Timex. 



WATCH FOR N€XT MONTH'S N€W R€l€RS€S 



56 South Third Street, Oxford. Pfl 19363 



THE minDUIDRE UNE OF SOFTWARE 
FOR TIMEX/SINCLAIR COMPUTERS 




MATRIX 


THE FAST ONE 


Z-TEXT 


INVENTORY 


FORECASTING 


SLIDE SHOW 


CRITICAL 


NUMERIC 


TOOLKIT 


SCREEN KIT 


PLANNER 


Store, organize 


A useful word 


CONTROL 


GRAPHS 


Creates and 


PATH 


Solves math 


Shortcut 


Routines to 


An all-purpose 


and retrieve 


processing 


Two ways to 


Analyzes 


runs video 


Gets complex 


formulas and 


commands for 


enhance 


electronic 


data instantly 


program 


keep track ot 


growth 


display shows 


scheduling 


draws graphs 


programmers 


screen 


spreadsheet 


$24.95 


$19.95 


inventories 


trends and 


$22.95 


under control 


$24.95 


$19.95 


displays 


$22 95 






$22.95 


plots graphs 
$22.95 




$19.95 






$19.95 




MONITOR 



GULP 



LABYRINTH 



PILOT 



GRAPHIC GOLF CROSSWORD ANAGRAMS WORD TEST MULTIPLE 



COSMOS 



Tests and 


Gobble your 


Can you find 


Cockpit 


A challenging 


Create and play 


Try to put the 


All kinds of 


CHOICE 


Hyperspace 


debugs 


way through 


your way 


controls 


18-hole 


your own 


scrambled 


question and 


Can you pick 


laser battles 


programs in 


mazes chased 


through 


that teach you 


golf course 


crosswords 


words 


answer tests 


the correct 


among the 


machine code 


by ogres 


3-D corridors'? 


how to 


$9.95 


$15.95 


back in order 


$15.95 


answer? 


stars' 


$19.95 


$15.95 


$15.95 


navigate 
$19.95 






$15.95 




$1595 


$15.95 



• FAST LOADING Mindware's proprietary 
Quickioad'* feature lets you load 
programs up to four times faster 
than conventional Timex/Sinclair 
programs. Quickioad software also 
alerts you to misloads, and lets you 
restart the tape from the point of 
interruption, without re-loading from 
the beginning. 



QUALITY TITLES Mindware software is 
written by top British software 
developers, including Picturesque, 
Hewson, Hilderbay, Asher, Campbell, 
Axis, Jones, Vortex and Silversoft. 



• USER-FRIENDLY Documentation provides 
clear instructions, iearning examples, 
and trouble-shooting tips. 
(All programs require 16K) 



I 
I 
THE ONLY PLAIN PAPER, DOT-MATRIX I 

PRINTER FOR THE TIMEX/SINCLAIR SYSTEM I 

I 

Mindware's MW-1 00 gives you the 

ability to make hard copies . 
of programs, data, mailing I 
lists, and screen l 
graphics 



SOFTWARE ORDER 



Title 




Postage & handling 

Total 

(Mass.residents add 5% tax] 



Price 



2.25 



SPECIAL PRINTER OFFER 

MW-1 00 printer - 

Two software titles fr ee: 



Retail value, $150-182.00 

119.0 

N/C 

N/C 

4.95 



Postage & handling 

Total 

(Mass. residents add 5% tax) 



Total enclosed is D 

Charge to □ vi 



check D money order 
>a D Mastercard 



Expiry. 



.Signature. 



SPECIAL OFFER: Ordera MW-1 00 printer for $1 19.00 

and get your choice of any two Mindware software titles 

FREE; plus 5 FREE rolls of paper (comparable retail value, 

$150-182.00). 

Thousands of MW-1 OO's have sold nationally at a retail price of 

$129.95 (Printer alone). 



Address 

City/State/Zip . 



Volume discounts 
available to dealers 
and schools. 
Send more info on: 

□ Quickioad software 

□ MW-1 00 printer. 



SEND TO: Eagle Sales Co./SY 

15 Tech Circle Natiek, MA 01760 
(617) 655-3368 



21st CENTURY ELECTRONICS 



THE FORTH CORNER 
Z-X FORTH $34.95 

MULT I FORTH $49.95 
(on eProm board 
STARTING FORTH 
>:: by I eo brod i e ) 
HARD COVER $22.08 
SOFT COVER $18.90 



shiPPiin9 and handling $1.58 



In 



ELECTROh 



6813 POLK STR. 

CUTTENBERG N.J. 

7093 

TELE. < 201)869-2:616 

SEND CHECK OR MONEY 
ORDER OR CALL FOR 
C.O.D. 





=> ONLY <= 



T/S 1000" PERSONAL COMPUTER p H * 4 - 00 49.95 

TIMEX SINCLAIR" PERSONAL PRINTER 8995 

84.95 

20.95 

it****** tt**tttta*t*t**t«** 

nenoT€CH ■ 

i imuuutuuuMutuu 



—2 KEY KEYBOARD 

&*G VU-LORD MOM ITER 



* 


64K $149.95 


* 


* 


32K 99.95 


* 


t 


16K 49.95 


t 


* 


HI RES 99.95 


1 


X 


GRAPHICS 


* 


* 


HEMOCRLC 99.95 


* 


* 


PRINTER 399.35 


* 


* 


RND 


* 


* 


INTERFRCE 


* 


* 


RS232 99.95 


* 


1 


INTERFRCE 


* 


* 


PfWflLLAL 74.95 


* 


t 


INTERFACE 


t 


* 


KEVBOIWD 99.95 


« 


* 




* 



21st CENTURY ELECTRONICS 

SALESDATA 2E 

THIS IS A TRUE SALES DATA AND ANALYSIS PROGRAM. ONE, THAT IS 
COMPLETELY USER FRIENDLY. THERE IS NO SETTING UP OF A FORMAT, TO 
MAKE THIS PROGRAM WORK. JUST PUT IN YOUR OWN COMPANY NAME, THE 
YEAR AND THE QUARTER YOU WILL BE USING THIS PROGRAM FOR, AND YOU 
ARE READY TO START PUTTING IN DATA. 

EVEN WITH ALL THE POWER AVAL I ABLE IN THIS PROGRAM. WE HAVE 
BEEN ABLE TO PUT IT INTO 16K SO THAT YOU CAN USE IT WITH THE 
BASE SYSTEM. 

THE PROGRAM COMES WITH FULL DOCUMENTATION AND IS MENUE DRIVEN. 
WE HAVE PUT A FEW ERROR CORRECTING ROUTINES IN IT, TO MAKE THE 
PROGRAM EASIER TO OPERATE. 

WHEN YOU PURCHASE THIS PROGRAM, YOU NOT ONLY GET THE PROGRAM 
BUT YOU WILL BE PUT ON OUR PREFERRED LIST. EHABELING YOU TO 
GET ALL UPDATED VERSIONS OF THIS PROGRAM FOR A NOMINAL FEE. YOU 
WILL ALSO BE ABLE TO PURCHASE ANY OF OUR FUTURE BUSINESS PRO- 
GRAMS AT A DISCOUNTED RATE. WITH OUR FUTURE PROGRAMS YOU WILL BE 
ABLE TO PUT TOGETHER A FULL BLOWN BUSINESS ON YOUR TIMEX/1088. 



121 CENTURY SALES REP0R1 i 

m MENUE • 

ENTER STARTUP DATA 
-.AFTER STARTUP DATA HAS BEEN ) 
(ENTERED DO NOT PRESS NO. 1 OR > 
< YOU WILL LOSE ALL THE DATA YOU ' 
CHflVE ENTERED 
( 2 > ENTER DATA 

READ WEEKLY TOTAL 
< 4 ) READ TOTAL SALES TO DATE 
CALL CUSTOMER RECORD 
TO SAVE DATA 
ADD h NEW CUSTOMER 
< 8 > SEARCH LAST YEARS RECORDS 

FIND AMOUNT OF MEMORY LEFT 
< • RFAD CUSTOMER LIST 



*******t*stt**tx*tt*t** **t 



2.' 1 s. <fc- C E M T U R ' i * E L. E C T R i 

SALESDflTfl 2E 
m =>34.95 < — 



JNICS 



t FLOPPY DISK INTERFRCE FOR TIMEX BUS $189.00 * 

* POWER RND CRBLES FOR 2 DRIVES $ 69.80 * 

* DOUBLE SIDE-DOUBLE DENSITY FLOPPY DISK DRIVE * 
± $193 95 ■ '$ 

* WORD PROCESSING SOFTWRRE PRCKRGECDISK >$ 35.00* 

-T- .+■ -T- -T> •+•+•'¥■ <T"^^T"¥' -T- <¥- -T- T- -T- -T- <♦■ ♦ •▼■ -T» ^T- <T' -T* -T- +> -T- -T- -T" ■?• 'T 1 %• -T- <T- -T- "T* «T" ■?• 'T- -T" "T 1 • T 1 -T- •¥• <T- ■¥• -T" ■T» 

* HUNTER 8K NON VOLITILE MEMORY KIT $29.95 * 

* BRRE BORRD W/MRNUflL 13.05 * 

* ASSEMBLED BORRD W/8K CMOS RRM 59.95 * 

* S. and H. $1.95 * 

* N.J. residents 6 PCT. SRLES TAX * 



*c m 

:*: M 

:*: Ec 
*: R 

:*in - -i 



:*::*::*::*::*:^:*:*C3*:^:^:^::*:*^^::*::*:* 
OFTSYNC SOFTWARE * 



OTHERSHIP 

IGHTGUNNER 

UPERCHESS 

ZOGS 
OOLK IT 
IORYTHMS 
EO ALERT 



, 35 



li 

13. 
14. 
14. 

14 L 

h3LTTICl 1 X TTI^* 
* 1 - 50 * 

residents .acid 
PCT. ^ 3. 1 <=? s. t:- ^. x 



35 * 



FOR INFORMATION OR PRICE ON THE TIMEX/ 1500 CALL OR WRITE 



The Magazine for Sinclair users and Tlmex/Slnclalr users 




July/August 1983 



Volume 3, Number 4 



DEPARTMENTS 

5 Letters 

75 Read This First 

7 SYNC Notes Grosjean 

116 Glitchoidz Report 

1 1 Try This Brodsky, Chandler, Marasa 

85 Just for Fun Adams, Koenig, Schuliz 

12 Perceptions Omstein 

INPUT, OUTPUT, and Other Confusing Things 

77 Timex Developments Grosjean 

1 20 Index to Advertisers 

SYNC AT THE WORKBENCH 

18 Robotics on a Budget Taylor 

YourTS1000/ZX81 as a controller 

32 So You Wish You Had Bought a TS2000 Day 

Color, sound, and a joystick on your TS1000/ZX81 

50 Connect a Monitor Lewart 

One transistor 

52 A Joystick for the TS1000 Stephens 

Adding an Atari joystick 

56 2K-4K Upgrade Glidden 

Expanding your RAM 



92 Adding a Counter in Hardware Puerzer 

Keeping time 

PROGRAMMING TECHNIQUES 

66 Stringing along with the ZX81 Wentlink 

Using READ and DATA 

74 RUNning with Reduced RAM Hartung 

Save time by lowering RAMTOP 

MACHINE LANGUAGE 

86 Machine Code and Your TV Screen Doakes 

Introduction to machine code, part 3 

REVIEWS 

76 The Votem Kelly 

Hardware review 

78 Memopak HRG Herriott 

Hardware review 

BUYER S GUIDE SUPPLEMENT 

80 Directory of Suppliers 

100 Improving Your Computer 

1 00 Extending Your Computer 

101 Programming Your Computer 

101 Using Your Computer: Programs 

105 Enjoying Your Computer: Games 



Staff 



Founder/Editor-in-Chief 
Managing Editor 
Contributing Editor 

U.K. Correspondent 

Art Director 

Assistant Art Director 

Typesetting 

( Operations Manager 

Fulfillment 

Advertising Sales Manager 
Advertising Coordinator 



David Ahl 

Paul Grosjean 

David Ornstein 

Martin Wren-Hilton 

Patrick Calkins 

Diana Negri Rudio 

Karen Brown 

Patricia Kennelly 

Frances Miskovich 

Carol Vita 

Karen Musmeci 

Claudia Reinhardt 



SYNC Magazine is published by the Consumer Computers and Fleetronies 
Division of Ziff-Davis Publishing Company. 

Larry Sporn President 

J. Scott Briggs Vice President. Marketing 

Eileen G. Markowit/. Vice President. General Manager 

Peter Blank Creative Director 



Volume 3, Number 4 

SYNC (USPS: 585-490; ISSN: 0279-570D is published bi-monthly by Ahl 
Computing, Inc., a subsidiary of Ziff-Davis Publishing Company. David 
Ahl, President: Elizabeth B. Staples, Vice-President; Selwyn Taubman, 
Treasurer; Bertram A. Abrams, Secretary. » E. Hanover \\c, Morris 
Plains. NJ 07950. Second class postage paid at New York, NY 10001 . and at 
additional mailing offi< 

Copyright c 1983 by Ahl Computing, Inc. All rights reserved. 

Permissions: Material in this publication may not be reproduced in any 
form without permission. Requests for permission should be directed to 
Bene Arnado, Ziff-Davis Publishing Company, One Park Ave.. New York, 
NY 10016. 

Subscription rates: USA: One year l(> issues), Mb: two years i \2 issues), 
S30; three years (18 issues), S42. Canada: S3 per year additional. Other 
foreign: S3 per year additional. 

For SYNC advertising information, contact Karen Musmeci. SYNC 
Advertising Sales Manager, Ziff-Davis Publishing Company, One Park 
Ne« York, NY 10016 (phone: 212/725-4216). 

All other correspondence should be addressed to: SYNC, 39 1 . Hanover 
Axe.. Morris Plains. NJ 07950. In U.K. to: SYNC, 10 Bishops Way, Sutton 
Coldfield. W. Midlands B74 4XU. 

Postmaster: Send address changes to SYNi '. PO Box 789-M, Morristown. 
NJ 07960. 



July/August 1983 B SYNC 



IMTGRCOMPUTCR IMC 



Expands the use of your TIMEX SINCLAIR 1000 



PROGRAMMING TOOLS 



• ASSEMBLER/DEBUGGER "ZXAD" (16K RAM). Write 
machine code quickly and easily with this professional quality 
two-pass assembler. Using ZILOG mnemonics with labels 
and symbols, 8 pseudo-ops, syntax checking, display or print 
listing with commands. Debugger includes examine/modify- 
ing, breakpoint with registers display, line renumbering occu- 
pies 7K. Comprehensive multipage manual. 

#PT4003 $18.95 

• STATISTICS PROGRAMS (16K RAM). Twelve programs 
with extensive directions for entering data. All programs use 
provisional mean formulas. 

Book: 200 page Introduction 

and listing NEW #BK9001 $1295 

6 cassettes NEW #BK902 $17.95 



r HOME MANAGEMENT m 

• BILL ORGANIZER (16K RAM). 
#HM5001 $14.95 

• CHECK BOOK MANAGER 
(16K RAM). 
#HM5002 $14.95 

• ADDRESS BOOK (16K RAM). 
#HM5003 $14.95 

• OCCASION CALENDAR 
(16K RAM). 
#HM5004 $14.95 



ENTERTAINMENT 




* We offer up to 16% discount on our 
packages. 

* We have special prices and terms for 
user groups, schools, colleges, stu- 
dents, research institutes and libraries. 

* We pay for shipment for all orders 
placed before August 31, 1983. 

* Please write or call us for free brochure 
and more information. 



• KRAZY KONG (16K RAM). A new version of the popular arcade game. This pro- 
gram has all the features of the original and is every bit as fast. 

#FG1013 $12.95 

• HOPPER (1SK RAM). Can you help Fergy and his friends get across the highway 
and back to the Lily pond? Includes crocodiles, logs, varying-speed traffic, etc. 

#1017 $12.95 

• TAI (16K RAM). In any other time or galaxy, the dust ball of the world called TAI 
would have been quite unimportant. Times change and the entire civilization will be 
betrayed. You have been chosen to defend TAI. The Galactic future depends on you. 

#FG1016 $12.95 

• GHOST HUNT (16K RAM). Gobble your way through a maze of Ghosts, Power 
Pills, etc., etc., very fast. #FG1014 $12.95 

• MAZE DRAG RACE (16K RAM). Drive through a giant maze 9 times the size of the 

screen; watch out for other cars, rocks, oil and ice. A really superb machine code 
game #FG1015 $12.95 



EDUCATIONAL SERIES 



• EDUVENTURE I (16K RAM). Answer the questions encountered in each classroom 
until you make it outside for RECESS and the surprise that awaits you there. (Grade 

levet K_3 > #ED3001 $12.95 

• EDUVENTURE II (16K RAM). Each new situation requires either your ingenuity or 
knowledge (or both) to avoid being sent to the principal's office. (Grade level 4-6). 

#ED3002 $12.95 

• EDUVENTURE III (16K RAM). Solve complex puzzles to outwit your teacher and 
achieve the highest scores. (Grade level 7-9) #ED3003 $12.95 

• EDUVENTURE IV (16K RAM). An agile mind and quick reflexes will get you 
through this maze of mysterious situations — to your DIPLOMA. (Grade level 10-12) 

#ED3004 $12.95 




Flexible Ribbon Connector 

MEMOTEC PRODUCTS 

MEMORY EXPANSIONS 

• 16K RAM #PL7002 $49.95 
•32KRAM #PL7003 $99.95 

• 64K RAM #PL7004 $149.95 

• HIGH RESOLUTION GRAPHICS 
(16K RAM) 

#PL7007 $99.95 

•PLUG-IN KEY BOARD 

#PL7011 $99.95 

• CENTRONICS PARALLEL INTERFACE 

#PL7005 $74.95 

• MEMOTECH RS232 INTERFACE 

#PL7006 $99.95 

PRINTERS 

• SEIKOSHA GP-100A PRINTER. The revo- 
lutionary low-cost dot matrix impact printer 

— Uses up to 9,5" paper. 

#PL7008 $349.00 

• SEIKOSHA GP-250X PRINTER. The most 
intelligent programmable graphic printer — 
Uses up to 9.5" paper. 

#PL7009 $449.00 

• PRINTER— INTERFACE CABLE. 

#PL7010 $19.95 

• MEMOCALC. Software on plug-in 
EPROM cartridge — Spread sheet analysis 

— Up to 7000 numbers (when used with 
64K). 

#BS200C $49.95 

• MEMOASSEMBLER. Plug in assembler. 
Code and edit a source program in Z80 
language, and then assemble into machine 
code. For writing flexible and economic 
programs. 

#PL7015 $49.95 

• MEMOTEXT. Plug in word processing. 
Brings commercial standard of text editing 
to your TS 1000. 

#PL7014 $49.95 



ATTENTION PROGRAMMERS: 

Be a part of a fast-growing corporation 

Repay better royalties for your high quality software for TS1000, TS2000, TI99-4. VIC-20. BBC. DRAGON, and ORIC-1 computers. 
Write or call us. Intercomputer Inc., PO. Box 90, Prudential Center, Boston, MA 02199 Tel. (617) 437-1190 



INTeRCOMPUTGRIliC 



^nds the use of your 1 IMbA SINCLAIR 1000 



INTERCONTROLLERtm 

Make? Your Life a Little Easier 

laboratory. Just plug JNTERCON mu hes |ndivldu . 

outer and program each o f the unit ™'* prog ramable 
&.y. The •NTERCONTROLLERn, ms w"™^ V ca n 
time intervals from rac ^°" s o Jjtr OLLE r,. units to your 
SS^^SKK^ 8 ^ #PL7013 $34.95 

SJRSSSS-i Based Programs To Load 

Many intercomputer P^™™^"^^^ 
state cartridges. Just P^9 a ran °9 t t0 {0U r car- 

KSSiSpS™^^ m 10 ' h3Vin9 iPStant 
L^Ky access ,o your favonte P«* J£ 1M1 $24 . 95 

FLEXIBLE RIBBON CONNECTOR 

ftr^n^.^^aSR A OLLSi S5? ?s7oOO. 
^SSS«a, system crashes caused 

by the RAM expansion movement. 

it^SSS^^-^ #PL7016 $17-95 




SOFTBOXt- 



sur i duak . „, 

SOFTBOX- has a DC PO^^hPttPr alternative for powering 
problems. 




Make?Machine Code Redundant 



QSAVE 

A Reliable Fast Loading System 

Xch operatel 16 times faster than the 
Sinclair system. 

T ? L?sset y t"nSace which plugs, nto 
your Timex 1000 to improve the s.g- 

an ON/OFF "switch are also built into 

this unit. . . 

2 Highly sophisticated software which 
win load and save programs at 16 
times their normal speed <ve 8K «n 
sees' 48K in 110 sees It works 
Sly well with AUTORUN pro- 
grams. BASIC or MACHINE CODb. 
QSAVE will operate with , ANY ^"ry 

software #PL7001 



M^.a/ thpm is no need to spend long 
SusTours writing and debugging your 
nroorams in laborious machine code - let 
RfcodeTdo all the hard work for you ... 
MCoder is the first real integer compiler 

irnorovement of the order of 75 times 

1 Load MCoder 

2. Write or load your basic program as 

3. RUN and debug your basic P'W™ 
■ 4. Compile your program using i a single 

print USR command. If you nave 
S a mistake MCoder will tell you 
exactly where, allowing you to correct 
it before it is too late. 
As an additional feature basic programs 

flexibility in your programming. 

#PT4001 $18.93 



hr S ough St ; a ny machine code software you 

want, list the program on } h f fc/e 6 "' =!;! 
U on another tape or print iU you have a 

printer. Simply ,oad 4^ and follow 

Sour computer and you may use A for 
other programs. #pj4002 $18.90 

DEALERS/DISTRIBUTORS PACKAGE 
^honf ordlrs: (617) 437-1190 7 days a week. 



TMail to: 



.ntercomputerjnc P.aBox90 H 
Prudential Center, Boston. MA 02iyy | 



Tel: (617) 437-1190 
Telex: 951141 COFAR 



I 



STOPPER 



No doubt you have felt the frustration of 
not bring able to see the listing or to 
make backup copies of machine code 




*, ^ ** -JSSSfflSSa-' ° ur FUU UME ° F SOmWRE 

COMING »« T|M£X S|NCLAIR 2000 



I 

I 

I 

I 

I 
I 
I 
I 
I 



D Check 

D Mastercard 

D Visa 

Account No 




"Directory of Suppliers" for the address. 
Note that the prices do not include state 
sales taxes where these are applicable and 
not all entries were clear as to whether the 
price included shipping. 

We want to emphasize again that the 
Buyers Guide is not a catalog, and we 
cannot guarantee the accuracy, complete- 
ness, or timeliness of the information. This 
is especially the case with prices because 
they are very changeable in such a com- 
petitive market. Check the supplier's cur- 
rent ads for up-to-date prices and full 



ordering information before making a de- 
cision or placing an order. If there is no 



ad, check with the supplier for full details 
before ordering. 



The TS2040 Printer and ROM Bugs 

ZX Users Group of New York 



Now that the Timex printer has made 
its appearance, Sinclair and Timex owners 
across USA will be adding LPRINT state- 



ZX users Group of New York, Box 560, Wall St., 
New York, NY 10005, 



FfJ 



ISYOUR 

Sinclair Working Hard, 
Or Hardly Working? 



n 






If you've been looking for a better way to keep your 
Sinclair busy, the search ends with Graphicomp. 

We've selected more than 60 unique software 
packages designed specifically for the ZX-81/TS1000. 

Choose from the largest variety of IK to 16K soft- 
ware available for education, programming, 
testing, and of course, the popular challenges 
and games. Write us for the name of the 
Graphicomp dealer nearest you. 
Dealer enquiries welcome. 



GRAPHICOMP 



55 York Street, Suite 100, Toronto, Ontario M5J 1R7 

It's time your Sinclair got to work. 




merits to their favorite programs. They 
will soon find out that there are some bugs 
in the LPRINT Command. The problem is 
not in the printer, but in the Sinclair 8K 
ROM. 

The first bug involves the improper 
printing of numbers between .01 and 
.00001. The program below, and the out- 
put following it, illustrates this. 
10 LET N=. 00001 
20 LPRINT N 
30 LPRINT .00001 
40 LPRINT STR$ .00001 
50LETN$=STR$N 
60 LPRINT N$ 
.0XYZ1 
.0XYZ1 
.0XYZ1 
.00001 

As you can see, lines 20 and 40 do not 
print ,00001 correctly. The May 1983 issue 
of Syntax describes this ROM error along 
with a hardware fix by putting a modified 
Sinclair ROM on EPROM. 

For those of us who do not have access 
to an EPROM programmer it is necessary 
to program around the bug. Lines 50 and 
60 above show how. 

Whenever you LPRINT a number which 
may be in the range of .01 to .00001, you 
should first assign it to a string using the 
STR$ function. Then LPRINT the string. 
Notice that using STR$ in the LPRINT 
statement does not correct the problem. 

Our ZX Users Group of New York has 
found some additional bugs. STR$ some- 
times does not work right with other string 
functions in LPRINT statements. For ex- 
ample, the following five LPRINT Com- 
mands do not give the expected results, or 
give error messages when they should not: 

LPRINT (STRS 100)(2) 
Gives: 100 (should be 0; also stops with 
error code 3). 

LPRINT LEN STR$ 10 
Gives: 100 (should be 2). 

LPRINT STRS 100 AND 
Gives: 100 (should be blank line). 

LPRINT VAL STRS 100 
Gives: 100 (correct, but then stops with 
error C). 

LPRINT CODE STRS 100 
Gives: 100 (should be 29). 

The moral of all this is, if something you 
try to do with LPRINT does not seem to 
work right, put the expression into a string 
and LPRINT the string. 

We hope that Timex or Sinclair will 
offer upgraded ROMs to correct these 
bugs. 5 



10 



July/August 1983 c SYNC 



try thi 



8KROM 

Type in the following lines: 

1 REM 1234-B 

10 POKE 16514- ,62 

20 POKE 16515,101 

30 POKE 16516,237 

4.0 POKE 16517^71 

50 POKE 16518,201 

_. BO PRINT AT 11,9;' 

a- 

70 RRND USR 16514- 

80 POKE 16515,30 

90 RRND USR 16514- 

1O0 GOTO 10 

Put the computer in SLOW mode. Press 
RUN and ENTER. After the program is 
run once, you can remove lines 10, 30, 40, 
and 50 and change line 100 to GOTO 20. 

Graphics notes: 
60: Inverse "SYNC MAGAZINE". Any 
message can be put here, but use the 
inverse for best effect. 
Our thanks to: 
Raymond Ma rasa 
652 Aspen St. 
Coquitlam, B.C. 
Canada V3J 3W2 



Type in the following lines: 
5 PRINT M (32 inverse spaces) 
10 PRINT AT 20, RND*30;'7* 
20 SCROLL 
30 RUN 

Press RUN and ENTER. 
Graphics notes: 
5: 32 inverse spaces. 
10: Inverse period. 
Our thanks to: 
Scott Brodsky 
71 TotmanRd. 
Lowell, MA 01854 



Type in the following lines: 
20FORN=lTO5 
30 PRINT CHR$ (36+ INT (RND*26+ 
.5)); 
40 NEXT N 



50 PRINT "###"; 

60 GOTO 20 

Press RUN and ENTER; press CONT 
and ENTER for another screen. 

Line notes: 

20: 5 letters. 

30: A random letter A-Z. 

50: 3 spaces after each word (8 * 4 = 32 
= a full line). 

Author's comment : This is the first Basic 
program I wrote. It is a simple one to 
produce a screen full of 5 letter "words" 
made up of letters picked at random. I ran 
the program and then stared at it and the 
screen for a long time. Then I decided to 
send by ZX81 back to be fixed. Then I 
stared at the screen some more . . . 

Our thanks to: 
Eric Chandler 
228 Arlington St. 
Lynchburg, VA 24503 EH 



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An introduction to Sinclair graphics - 
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July/August 1983 c SYNC 



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11 



perceptions 



David Ornstein 



INPUT, OUTPUT, and Other Confusing Things 



In this issue Perceptions will take up 
I/O (Input/Output) ports. The funda- 
mental issues are discussed, and a sample 
method for their application to the 
TS1000/ZX81 is described. 

Introduction 

I sit in front of a video terminal. A 
cursor flashes in a corner of the screen. I 
press the key labeled ENTER on my com- 
puter. From behind, I hear a 'ka-chunk' - 
the familiar taka-taka-taka of my main 
printer. 

Soon a message appears on the screen. 
It reads: PRINTING COMPLETE. O.K. 
TO CONTINUE?" I activate the tired 
muscles in my arm, reach to the keyboard 
and, extending my index finger, press the 
Y key. The red LED on one of my disk 
drives begins to flash! once, twice, and 
again. Soon they glow constantly. 

Then, to my great surprise, the speech 
section of my computer wakes from its 
day-old sleep, and begins to recite the 
alphabet. Next each light in the room 
begins to cycle: first off, then on, then 
off, and then back to its original state. 
The television in the next room goes on, 
and I hear gunshots from the western 
movie. I decide to sit back, smoke a 
cigarette, and go quietly out of my mind 
contemplating the reason for my com- 
puter's apparent loss of its mental 
faculties. 

Contemplation, as usual, leads me no- 
where. Pressing, repeatedly, the RESET 
button seems to have little or no effect on 
its trip into never-never land. I pull the 
plug. 

The above scenario may sound like an 
excerpt from HAL's adventures in 2001, 
but it is not. It is a scene that occurred in 
my study a few nights ago. Such an occur- 
rence is, admittedly, a rare occurrence in 
my house. It is, however, more likely to 

12 



occur in my house than in the average 
house in, say, a less technically-oriented 
environment. It usually comes about 
during the testing of some new feature 
that I am adding to my computer. Often 
an I/O port. I scramble a few wires, plug 
in a board upside — down, or backwards, 
—whatever. 

This time, however, the event was un- 
precedented: I had a witness. Someone 
would, finally, be there to back me up 
when I told my friends what had 
happened. 

My friend (or should I say savior?), a 
novice in the computer field, was amazed. 
"What is happening?" and "Can I help?" 
seemed to the most frequent comments. 
Once I had cleared up the mystery in my 
head (a solder bridge), we went to the 
local coffehouse and discussed music, 
good coffees, and the events of the 
evening. 

Not surprisingly, the evening's events 
dominated the conversation. What had 
happened, he wanted to know. What 
ensued was an explanation of I/O. Input/ 
Output: those operations which concern 
the computer's communication, and inter- 
action with the outside world. Soon the 
cafe closed, and we returned home. The 
discussion continued, and continued, and 
continued.... Upon reflection the next 
day, it occurred to me that the material 
that we discussed would make a good 
article. What follows is just that: a sum- 
mary of that discussion. 

What Is an I/O Port? 

My friend, having heard me use the 
term dozens of times that night in conver- 
sations with myself, asked me: "What is 
an I/O port?" An I/O port is a channel, 
through which, a computer "talks" to the 
outside world. When a computer wants a 
printer to print a particular character, it 



sends, via an I/O port, the code that 
represents the desired character to the 
printer. The printer then decodes the 
charater into the proper internal format 
(i.e., dots), and eventually yields a char- 
acter on a piece of paper. 

More properly, the computer sends the 
character that it wants printed to the 
printer via an output port connected to 
the computer. Hopefully, a sane printer is 
listening to the output of that output port. 
The printer will notice that the computer 
has sent a character to it, and it will read 
that character through its internal input 
port. 

Noticing the questioning look on my 
friend's face, I ordered two more cups of 
coffee, and dove head on into a detailed 
description of I/O ports. 

Types of Ports 

There are two kinds of I/O ports: paral- 
lel and serial. Parallel ports are the easiest 
to understand, so I will tell you about 
them first. 

A parallel port transfers data, usually, 
eight bits at a time. Eight bits, as you 
know, comprise a byte — the basic chunk 
of data in a microcomputer. Larger com- 
puters, using parallel ports, may transfer 
as many as 32 bits in a shot. It depends on 
how the processor is organized. The 
Timex/Sinclair 1000 uses an eight-bit 
microprocessor, the Z80. The Z80 has an 
eight bit data-bus. A data bus is, concept- 
ually, a series of wires (i.e., eight) that 
carry around data. The Z80, having eight 
of these "wires," will use an eight bit I/O 
port. I reached for an "engineer's best 
friend" — the napkin. 

"Let me illustrate," I said. I drew a box 
with eight lines coming out of each side. 
One line extended from the top. This is a 
simple I/O port. (See Figure 1.) 

Eight LEDs (Light Emitting Diodes) are 

July/August 1983 c SYNC 






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arranged so as to light when their corres- 
ponding control lines are activated. To 
make them all light, the computer must 
activate all the control lines. It does this 
by sending an FFh (1111b) to the output 
port. To turn on LED 2, LED 5, and LED 
6, the computer must send a 001 10010b. 
To send data the computer must place 
the desired data on its data bus, and 
activate the STROBE line on the output 
port. Activation of the strobe line says, in 
effect, to the output port: "Take what 
I'm giving you on the data bus. Put it on 
your output lines, and keep it there— even 
if I go away. Don't change it until I tell 
you to (i.e., activate the STROBE line 
again)." This effect is known as latching. 
The device (an integrated circuit, prob- 
ably) that performs the action of latching 
is known as a latch. When one piece of 
data is latched, it stays on the output of 
the latch — until something new is 
latched. 

Address, Control and Data 

When the computer wishes to read data 
from a keyboard, or read data from a 
cassette tape recorder, or send characters 
to a printer, it must know how to tell all 
those devices (i.e., I/O ports) which one 
is being talked to. In the case of an aver- 
age computer, there may be as many as a 
dozen— or more— output ports. How does 



.Figure 1. 



STROBE 



DO 



Dl 



D2 



D3 



D4 



D5 



D6 



D7 




it (the computer) know which STROBE 
line to activate, how does it "activate" 
them, for that matter? 

Let me try to explain by way of an old 
analogy. Imagine, that the printer to 
which a character is to be sent lives on a 
road, He— Mr. Printer, that is— has a mail- 
box. If he has a mailbox, then he has an 
address. When Mr. Printer's friend the 
computer wants to send a message 
(output) to Mr. Printer, he gives that 
message to Mr. Mailman (the Data Bus). 
Mr. Mailman carries the message to Mr. 



Printer's mailbox (Output Port.) Mr. Mail- 
man then puts it into the mailbox, and 
strobes it (i.e., he raises the "mail-here" 
flag). Actually, the mailbox combines 
both the output port of the computer and 
the input port of the printer. 

When Mr. Printer is ready to read his 
mail, he goes to his mailbox. He removes 
the message, and reads (processes/prints) 
it. He also signals to Mr. Computer that 
he is ready to receive more mail by lower- 
ing the "mail-here" flag. This is a common 
feature of I/O port arrangements. It says 



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14 



July/August 1983 • SYNC 



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to the sending device, that the receiving 
device is ready to accept more data 
When the data is sent to the I/O port, the 
DATA AVAILABLE flag is set. (This 
was the "mail-here" flag in the above 
example.) This interaction between out- 
put device, and input device is called 
handshaking. 

Without proper handshaking, at least 
two fatal occurrences are possible. First 
is the case where the output device is 
sending data faster than the input device 
can read and process it. An extreme 



example might be the case in which a 
computer is sending characters at a rate 
of 150,000 cps (characters per second). 
An average printer can read characters 
at a rate of approximately 150 characters 
per second. Every second, the printer 
would miss 149,850 characters— clearly 
an unacceptable number. Handshaking 
solves this problem. The computer reads 
the DATA AVAILABLE flag that it set 
(i.e., turned on). It waits until the printer 
has reset the line before sending another 
character. 



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Please add $2 to each order 
for postage/handling 

Distributor Inquiries Welcome 



The other problem arises when the 
computer is reading data from a device 
that is presenting data slower than the 
microcomputer is reading. A keyboard is 
such a device, and a keyboard is a com- 
monly used device indeed. The keyboard 
has an output port, in this example. When 
the user presses the W key, the output 
latch grabs the code for a W, and holds it 
on its output. 

Meanwhile the keyboard is being read 
by the computer 50,000 times per second. 
How many times, in that second, do you 
think the computer will read the key W. 
Clearly, the synchronization provided by 
handshaking is critical. 

Returning to the issue at hand, a typical 
microprocessor, such as the Z80, has an 
eight bit data bus, a 16 bit address bus, 
and a collection of control lines. These 
control lines indicate the conditions of 
the data bus, and the address bus. They 
dictate, for example, that the 16 bit num- 
ber on the address bus is the address of a 
memory location, and that the data on 
the data bus should be written into that 
memory location. They might specify that 
the address on the address bus is currently 
specifying a particular input port, and 
that the designated port should place its 
data on the data bus for the Z80 to read 
into one of its internal registers. 

The address bus, being 16-bit wide, can 
specify any of 65536 addresses 
(65536=2**16). The number 65536 is 
often referred to as 64K. One "K" is 1024 
(2**10). The 64K addressing area (address 
space) of a computer is usually filed with 
various items: RAM, ROM, and I/O 
ports. The Timex/ Sinclair 1000's memory 
space is shown in block form in Figure 2. 

Figure 2. 



FFFF 

cooo 

A000 
8000 

4000 
2000 
0000 



RAM 



ROM 



ROM 



RAM 



ROM 



ROM 



16 



In the next issue, I will continue dis- 
cussing I/O ports. I will describe a way to 
open up some of the apparently filled 
address space of the Timex/Sinclair 
1000. 

Until next time, same relativistic time 
period, same non-Euclidian universe. B 

July/August 1983 ° SYNC 



FLOPPY DISC 
INTERFACE 




■ m 



$149 
$119 



COMPLETE 



KIT 



Sinclair ZX81 or Timex 1000 



Available either completely assembled, ready 
to just plug-in or in an easy-to-assemble kit 
with the following features: 

• Interfaces with your Shugart SA 400 or 
any equivalent 35 or 40 track drive system 
(please specify when ordering) • Loads 16k 
program reliably in seconds • Compatible 
with all RAM expansions • Direct plug-in to 
rear connector or bus expansion • DOS on 
2732 ROM • DOS commands from direct 
mode or from your BASIC program. 

• DOS commands: 

IN1T DSAVE DLOAD DIR STAT 
CREATE WRITE READ KILL NEWD 




CEHTROniC 



INC. 1101 Bristol Road, Mountainside, N.J. 07092 



Please send 



floppy interfaces. 

□ Completely assembled at $149 each □ Kit form at $119 each 
I am using a D 35 track drive □ 40 track drive 

D Check enclosed □ Money Order enclosed 

Charge my □ VISA or □ Master Charge 

No. Expiration date 



Please send details on other new products: D Package Floppy Disc Systems 
D Keyboard Beeper □ Tape Loading Aid □ 16K and 64 K RAM Packs. 



Name 



Address 
City 



A Name You Can Depend On 



State/Zip 

Add $3.50 for shipping and handling. NJ. residents add 6% sales tax. 
• Check • Money Order • VISA • Master Charge 



RobotiCS On a Budget Bruce C. Taylor 



The Project 

A little over a year ago I decided to 
start building a robot. I had no idea that it 
would lead to a project fully controlled 
by a computer. However, as I started 
reading more about robots and the ro- 
botics law, I realized that a true robot 
had to be a self-contained entity able to 
operate as independently as possible. At 
that time I did not even know what a 
ZX81 was, but, after a few months into 
the robot project, I bought my first ZX81 
computer (the family now owns two). 
Even then I did not immediately realize 
the possibilities of ZX81 control. About 
three months later after reading about 
the expansion possibilities of the ZX81, 1 
decided to try to combine the ZX81 with 
the robot. 

If you are not interested in such a large 
computer control project, the hardware, 
software, and interface methods de- 
scribed here can easily be applied to a 
smaller project such as a robot arm. 

The Robot 

I will not describe the actual construct- 
ion of the robot in any detail. The design 
for the robot was based on the Radio- 
Electronics magazine reprint series of 
articles titled, "Build this robot for under 
$400." 

Although my project robot has many 
similarities to the RE Unicorn-1 robot, it 
also has many differences. As complete 
as the series of articles was, there were 
many errors and incomplete explanations 
of the design. 

The basic improvements on the phy- 
sical design are as follows. The diameter 
of the body was reduced to sixteen inches. 
It was obvious that a body any wider, 
with arms added, would have trouble 
navigating through household doorways 

18 



and other tight spots. The drive wheels 
were placed in the front to pull the robot 
around and aid in traction. This moved 
the battery to the rear and aided stability. 
The base was made the same diameter as 
the body for aesthetic reasons. Although 
small access doors were located in both 
the front and back of the base, the re- 
quired access to the base was achieved 
by making the entire base plate of the 
upper body, with turntable, hinge back- 
ward to allow full access to the inside of 



the base. And finally, the computer with 
expansion board was located on the top 
and underside of the hinged lid. 

To save money and learn as much 
about the input/output circuitry as pos- 
sible I purchased the Computer Con- 
tinuum expansion board and the Zodex 
RX-81 input/output boards in the bare 
board form and built them up from com- 
ponents purchased separately. I built up 
all the other boards and even etched some 
myself. 



Figure 1. Power Supply. 









D2 

kl 














|sj 
















ICl 
V in V out 

Adj 






FC1 












+ 
r- 9V 


rv-v-v-> 


Dl^Rlf C2 

11 




+ 

12V 


]C3 










out 


in FC2 






CI 






— / r VW^i 






R2 f 










A 





















ICl LM350, 3 Amp adjustable power regulator 

D1JD2 1N4002 

Rl 120 Ohm, 1/4 watt 

R2 5K Ohm adjustable pot (10 turn) 

CI .1 MFD, 25V 

C2 1 MFD, 15 V 

C3 2300 MFD, 33VDC, 50V surge 

FC1,FC2 125 uH, 3.5 Amp hash filter choke 

Note: Heat sink ICl well (3 to 4 Sq inches) 



July/August 1983 c SYNC 



Photo L Looking through the dome. 

Photo 2. Robot lid opened showing ZX8I and 
power supply. 

Photo 3. Dome removed showing J6K RAM, CC 
expansion hoard, 2 RX81 I/O boards. 

Photo 4. 5 volt DPDT relay board: Wiring side. 




Mte 



Photo 5, Front view of robot. 

Photo 6. 5 volt DPDT relay board: Component 
side. 

Photo 8. Transistor switch board: Component 
side. 

Photo 7. Transistor switch board: Wiring side. 




2. 




niUMM 1W «Mwm '• *jm 




^F " , ^*»-. WE.) yjjtfj ?mvi .-H?l "JPC- 

1 " ) 

^k|* rivy u i f I P**t k j *> » i * , • — 




1 


1 


1 

If 









ft 



July/August 1983 c SYNC 



19 



KVC, INC. INDIANAPOLIS, 



INTERFACE 
JOYSTICK 

Interface to use 2 joy- 
sticks W jth the ZX-81 
games. Work instructions 
detailed to prepare their 
own programs controlled 
by joystick and to adapt 
he ones already existing 
» be controlled by joy- 
sticks. y ^ 



THE WINNING 




MEMORY 
EXPANSIONS 

Highest Technology and 
gold plated connectors 
tor unbeatable results All 
Piggyback port for other 

16K = S54 

32K = $ 95 

64 K = $135 



i°V r «8r/TIMEXl000 ^ 
ALL FROM O/VfMANUFACTUf 




OS SOUND GENERATOR 

^rra ,6 '— mm 3 

in»om. when ,he £^SS is^t °' ' ^"^ ^ «° 
omelerandampHf^C " 9 V ° ,Ume P° ,e "«- 

$49 




CENTRONICS INTERFACr 
Interface to connect the ZX-81 ,„ a 
"hich can work uwl er this norm 
PRINTER CABLE $16 




RIBBON CONNECTOR 
Ertends the ZX-81 BUS to avoid 
^ores in the memory and ~* 
Pheric connection. 5^9 




INTERFACE FLOPPY D(SK(S0GA 



than 20 seconds. 



»ng m less 
$115 






PROFESSIONAL KEYBOARD 

"Keys • Fu »V assembied No soidenng Outlets ,o,M.C. EAR 

$89 




QS 

PROGRAMMABLE 

CHARACTER 

GENERATOR 
Allows to program T28 
"ew graphic characters. 

them. Swtch ON/OFF 
to select new charac- 
ters or Sinclair charac- 
terS $45 



INDIANA PRESENTS 
COMBINATION 



CROAKA 
CRAWLA 




SUBSPACE STRIKER 

It comes from out of nowhere and 
then vanishes back into the ether. 
With your deadly antimat torpe- 
does, you unleash havoc in the 
Federation's Spacelanes. 
Plus Zor battle of the robots. 



SUBSPACE 
STRIKER 



CROAKA CRAWLA $12 

Author. John Field 
It's not easy being a frog what 
with the trucks and lods, the cro- 
codiles and turtles. The continual 
battle for survival, struggle with 
the universe ... Us frogs do some- 
times get a little carried away, 
see you on the far bank. 
Special Features: Flies, croco- 
diles, Sinking turtles, Inverted 
logs, Progressive difficulty attack 



GALAXIANS 
& GLOOPS 



\fi v ! 



MUNCHESS 



"1WW 



.«■*■■ 

■I ■!- Mi 



MUNCHESS $12 

Author: A. Laird 

Beware the Munchees, a board 

creaks in the time lost corridors. 

A ghostly presence, a rush of 

wind, a forgotten echo whispering 

around the house and following 

chuckle of ghosts rolling forward 

on cold breezes ... 

Special Features: Ghostly ghosts, 

pills and fruit, munchy munchees. 



SOFTWARE Qwcksilvas 

latest bits make your ZX81/TIMEX 
1000 give you the best in exciting 
entertainment and fun 



PIONEER TRAIL 



S12 > 



Author: Marion Stubbs 

A Western adventure Featuring 
20 levels of play. 'Mind Game' 
plus shooting rifle speed uses all 
keys and is measured against the + 



se. This game is based on histo- 
rical data. 



PIONEER 
TRAIL 



CI 



TRADER 



SCRAMBLE 







mmw^-- 


s^^^ 




Ira 






■Lz5f 



TRADER 

A trilogy of 16 K programs that combine to give an epic 48K 
graphic adventure. As a galactic trader, you deal with some very 
bizarre customers indeed. Will you live to tell the tale? 
It is hard enough to look at an amorphus hydrosilicon blob from 
Psi, never mind swing a deal with one. But when they ask to pick 
your brains, do you really know what they have in mind ...? 
As an intergalactic door to door salesman, you do the rounds of 
the Moons od Meridien, a beautiful gas giant in the Altair system 
some 16 light years from Earth. The life is tough, the bargaining 
hard. You can gain fame and fortune or end up spaced out in a 
Deltan hellhole. 

You deal in Synthomunch and Boosterspice, Petrochem and 
Gold. You meet other ex-Terrans and unimaginable alien creatu- 
res. You go gravity diving in your little spacehooper 'Pegasus' 
and have to land on a solid chunk of Uranium to pick up fuel. 



GALAXIANS & GLOOPS 

Author: T. Beckwlth 
The peaceful Fragnn battle the 
large Wobbly Galaxian birds with 
a device built of dragon gut and 
with small furry bombs, Splach, 
PI oof, Splach, Ploof, Tank, Ploof ... 
A keen eye and a fast hand help. 
Special Features: Two types of 
swooping, bombing, galaxian, All 
fully adjustable. 

GLOOPS; An amazing maze gs 



QS SCRAMBLE 

Author: Dave Edwards 

A landscape of mo 1 " 
teaus and val lies sli' 
ship as waves of all 
firing from above an( 
up from the ground, 
explode below as yo 
ny craft... 
lei Fea 
Rindom 





ttware 
Also "EN ES 



- 3\\ 



PLEASE SEND YOUR ORDER TO: 

MAIL KARTES VIDEO COMMUNICATIONS, INC.. DIV 

COMPUTERS & PERIPHERALS 

10 EAST 106 th INDIANAPOLIS. INDIANA 46280 
PHONE 800-428-6163 (except in Alaska and Hawaii) 
800-692-6048 (m Indiana) 



It 
\t 

h 

n AMERICAN EXPRESS 

□ VISA 

□ MASTERCARD 

D cheque/p.o. Name _ 
Address 







*Z KARTES VIDEO COMMUNICATIONS, INC. 
MZT COMPUTERS & PERIPHERALS DIV. 

TWHKF" 10 EAST 106 th. INDIANAPOLIS. 
j//wC INDIANA. 46280 


■o 

3J 


*••*• 






ITEM 


PRICE 


TOTAL 


(/) 










ii 










■ 




















■ • 










u 










< 










> 




SHIPPING and HANDLING 


4,00 


r 








TOTAL 


i 





CALL TODAY TOLL FREE 



Well keep 
your Sinclair summing! 



N£\N 




NOW ONLY 



OUR $jW&NCLAIR AND TIMEX OWNER-PROTECTION SERVICE PLAN 
N WILL SAVE YOU MONEY 



Timex too! 

Typical repair charges for a 
Sinclair ZX81 can run from $25 or 
$50 \p to the rpplprpmpnt rnc* of 
the unit. So why take chances? 
MicroSync will guarantee unlimited 
service for one year, parts included, 
at one low price. With return postage 
and handling paid. Plus our VIP 
treatment for fast turnaround. 

MicroSync's experienced 
technicians are ready to service 
your ZX81 or Timex/Sinclair 1000 
with factory replacement parts. We'll 
return it promptly and we'll quality- 
check your unit before it leaves our 
service center. 

We made over 10,000 
Sinclair's tick last year. 

Sinclair equipment has a great 
reputation for reliability But almost 
all computer equipment requires 
service at one time or another. 
We've been repairing Sinclairs ever 
since their first glitch. 




MicroSync is THE Sinclair 
authorized Service Center. 

Your Sinclair computer is a 
remarkable assembly of electronic 
components, some unique to 
Sinclair technology Our Sinclair 
personnel have been trained on, and 
service only Sinclairs. 



We have the experience it takes. 
We have the parts on hand. 

So act now! If your unit is less 

inafi C7u u8y5 Oiu yuu Ccifi puioiidbt; 

our Owner-Protection Service Plan 
for only $1^5. 



Mail To: MicroSync 

162 Marlboro St 
Keene NH 03431 

Please send Maintenance Agreements for 
the equipment listed below: 

ZX81 or Timex/Sinclair 1000 

Less than 90 days old 

(include proof of purchase) $10.00 ea. 

Over 90 days old $29.95 ea. 

16K RAM 

Less than 90 days old 

(include proof of purchase) $10.00 ea. 

Over 90 days old $29.95 ea. 



Total Enclosed 

Serial nos. 



U.S. $ . 



□ check □ M/C □ VISA 

Card# Exp. 

Name 

Address 

City 



.State Zip. 



The fine print. MicroSync's Maintenance Agreement covers all parts and service for 12 months 
after the expiration of original warranty. For units over 90 days old, coverage is for 12 months 
from the date of the Maintenance Agreement. Kits or modified units may require a surcharge 
MicroSync may not repair units damaged by abuse or negligence. Liability extends to repair or 
replacement only. 



MicroSync 

AUTHORIZED SINCLAIR SERVICE 



r 



The Power Supply 

The biggest problem on the electronic 
side resulted from choosing to run every- 
thing from a single 12 volt battery. The 
DC motors and the controlling relays 
caused problems because the voltage and 
amperage (frequency) spikes which they 
generate wreak havoc on the computer. 
The single battery, originally a large 
motorcycle battery since replaced with a 
small car battery, simplified the power 
management problem. 

The final solution to the spike problem 
had an added benefit for the ZX81 used 
as the home computer. If you have never 
tried to use a small computer in Europe, 
with the "spikey mains" as the British 
refer to their noisy wall power, you cannot 
dream of how many ways a computer can 
bomb. The problem is the same here in 
West Germany where I am currently 
living. 

The power supply (Figure 1) solved all 
spike problems. For the robot, the 12 
volts in comes from the battery. For a 
home computer application, the 12 volts 
in would come from a rectified 12 volt 
transformer output. 

The key to the success of the design is 
the large can-type capacitor (C3) and the 
hash chokes. The capacitor is available 



from Jameco, and the hash chokes were 
ordered from Mouser. The power supply 
works so well on my wall-powered ZX81 
that all problems previously attributed to 
LOADing and SAVEing glitches have all 
disappeared. Also, with the large can 

Figure 2. Relay Functions. 



RLY 

1 

2 

3 

4 

5 

6 

7 

8 

9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 



RLY 



4 
5 
6 

7 

8 

9 

10 

11 
12 
13 
14 
15 
16 
17 
IB 
19 
20 



DO-7 

1-5 

1-6 
1-1 

1-2 

1-4 



2-4 



2-D 

2-6 
2-7 
2-8 
1-7 
1-8 
Gnd 



RX-81 Output 
wire color 

blu/sht 
wht/blu 
wht /grn 
grn/wht. 
wht /gry 
gry /wht 



wht /grn 
grn/wht. 
wht /gry 
gry/wht. 



hi u/wht 
wht/blu 
org /wht 
wht /org 
org /wht 
wht /org 
bin 



Function (Motor Drive) 

Upper body rotate left 
Upper body rotate right 
Left drive wheel forward 
Left drive wheel reverse 
Right drive wheel forward 
Right drive wheel reverse 
(not used) 
(not used) 
Left shoulder down 
Left shoulder up 
Right shoulder down 
Right shoulder up 
(not used) 
(not used) 
Left elbow down 
Left elbow up 
Right elbow up 
Right elbow down 
Right hand close 
Right hand open 



Figure 3. RX-81 Output. 



PC conn 

10 

11 

6 

7 

8 

4 

20 

21 

12 

13 

14 

15 

16 
17 
18 
19 

9 



4-5 volts 

RX-81 output board #1 wired as "out 7" 



Trans 
switch 



Base 
(In) 

L 
M 

F 
H 
J 
D 
X 
Y 
N 
P 
R 
S 

z 

E 

T 
U 

V 

w 

K 



Coll 

(out) 

10 

11 

6 

7 

8 

4 

20 

21 

12 

13 

14 

15 

no 



16 
17 
18 

19 
9 



2,B 

(emi tiers) 



capacitor, the house lights can moment- 
arily dim with no effect on the computer. 

The Control Relays 

The heart of the robot control is the 5 
volt double pole double throw relays 
driven by the computer output which in 
turn activate the 12 volt robot motors 
and solenoids. The functions of these 
relays are listed in Figure 2. Although 
only sixteen are used, the 44 finger circuit 
boards used are capable of handling up to 
twenty relays. In my design these relays 
are double buffered from the computer 
output drive with both transistor switches 
and small DIP relays. The 12 volt relays 
(5 volt coils) are wired similar to the RE 
reprint layout with some important dif- 
ferences which will be explained later. 
Figure 3 gives a complete wiring table 
from the RX-81 output through the 12 
volt connections to each motor/solenoid. 

I will now quickly walk you through 
Figure 3 describing the control of relay 
#1 and then explain each component in 
more detail. 

Relay # 1 is controlled by the output of 
D4 from one of the RX-81 input/output 
boards. D4 is designated as 1-5 meaning 
that it is the fifth of eight parallel outputs 
on the first RX-81 output board. It is 



DIP 

relays 



Coil 

(in) 

L 
M 

F 
H 
J 
D 
X 
Y 
N 
P 
R 
S 

L 

E 
T 
U 

V 

w 

K 

c 



Contact 
(out) 

10 

1 1 

6 
7 
8 

20 

21 
12 
13 
14 
15 

4 
16 

17 
18 
19 

9 
1 



5v 
relays 



Coil 
(in) 

20 

17 

R 

L 

6 

21 

15 

N 

K 

7 

19 
P 
M 

8 
5 
.i 
IS 
4 



Conlacl 

(out) 

W 

V 

11 

12 
D 

C 



E 

F 



U 

T 
J 
H 

10 



A 



RX-81 output board #2 wired as "out 6". 



Example: Output DO from board wired as "out 7 M is listed above as 1-1. 



July/August 1 983 c SYNC 



23 




Peak 



Cassette Software for the ZX81 
and the Timex/Sinclair 1000 



TEXT & PRODIR 

TEXT - A program for easy editing, storage 
and display. Recall pages of reports, letters, 
etc. without splitting words at the end of a 
line. PRODIR - A programmed directory to 
organize programs and ease loading. 
PRODIR can provide a table of contents for 
reports or chapters contained on tape. Use 
TEXT & PRODIR with your printer 
$10 16K cassette 

TEXTII 

The only program you'll need to compose 
edit and save pages of text. Pages are recalled 
without splitting words. For speed the 
program now utilizes machine code. Includes 
PRODIR. TEXTII has a variable no. of 
characters per line to accommodate your 
printer. Includes a string search routine, a 
line renumbering routine to open up space to 
insert new sentences and paragraphs, and an 
inverse video screen function 
$20 16K cassette 

DATAPLOT 

Plot stock prices, interest rates, scientific 
data, etc. with this program. DATAPLOT 
plots positive and negative free formatted 
data stored in REM statements. Draws and 
labels the axes, titles plots and connects data 
points. DATAPLOT will also draw figures, 
plot from an equation and plot on a grid if 
necessary. Use with your printer for a copy of 
your plot. 
$10 16K cassette 

STRING 

A routine you can add to vour oroarams to 
search for commands, words, and phrases. 
Perfect for locating phone numbers, program 
statements, etc. 
$2 2K listing 

INVERSE VIDEO 

Software machine code routine to reverse 
your screen to white characters on a solid 
black background. 
$4 1K listing 



j n 

Call (303) 441-01 10 for Visa/MC Orders. 

Please rush me the following proqrams- 

D TEXT & PRODIR D STRING 

□ TEXTII q INVERSE VIDEO 

D DATAPLOT 

Enclosed is $__ or charge my 

VISA □ MASTERCARD □ 

CARD NO EXP DATE _ 

SIGNATURE _____ 

NAME: 



(Please Print) 
ADDRESS 



CITY/STATE/ZIP: 

Peak 



P.O. Box 8005, Suite 231 
Boulder, CO 80306-8005 



Figure 4. Transistor Switches {Total of 16). . 

2N2222 



+3.5V., 
(RX-81 
output 
activated) 




To DIP relay 
coil (gnd side) 



Rl 220 Ohm 1/4 watt 



gnd 



connected by a blue with white stripe 
wire to finger 10 of a short PC board 
which is plugged into the circuit loads, 
depending on the size of the DC motor or 
solenoid driven. 

Large DIP mounted relays of sufficient 
amperage can be used but they can be 
expensive ($4-5 each). I found some min- 
iature 6 volt DPDT relays rated at 3 amps 
which were cheaper and worked quite 
well. One source is the All Electronics 
Corp. at only $1.75 each. Sixteen to 
twenty of these can be packed on a 4 x 5 
inch PC board, although the more expen- 

Figure 5. DIP Relays (16 total). 





1 

2 

6J 

7 




14 










i 


13 

9 
- 8 






D2 
H>f- 








CI 










in 


I 


■■ill — w— 

D2 


II I" 



-in* +5V + 5V +5V 

out** 

D2 1N4148 

CI .01 MFD, 10V 

**For DIP #1 this would be wired to 
connector L. 

•♦For DIP #1 this would be wired to 
connector 10. 



24 



sive high amp rated contact DIP relays 
would not have to be packed so closely. 

An example of both the forward and 
reverse relays is shown in Figure 6. They 
are wired together to prevent accidental 
shorting of the output to the motor. Each 
of the two relays for each motor (one for 
forward and one for reverse) provides 
opposite polarity power. If you made no 
special wiring provision, it would be pos- 
sible to activate both relays at the same 
time and cause a direct short circuit be- 
tween + 12 volts and ground. Two extra 
wires between the two relays, along with 
a modification of a direct hookup, protect 
against this. 

If you look at Figure 6, you will see 
that the coil input (+5 volts) to the right- 
hand relay coil (relay #1) will not cause 
the coil to be activated unless relay #2 
(lefthand relay) is not activated. This is 
because the coil of relay # 1 has no ground 
to complete the circuit unless relay #2 is 
in the normally closed position. Notice 
that the ground for relay #1 coil is sup- 
plied through the normally closed contact 
of relay #2. This way, even if both the 
reverse and forward circuits are activated 
at the same time, only one will work. 

Also note the diode and capacitor pro- 
tection on these relays. This feature is 
especially important as the unloading of 
these relays introduces a lot of unwanted 
into the electrical circuits. 

For some motors in your robot the 12 
volt output of the relays in Figure 6 will 
be hooked directly to the motor leads. 
However, you may wish to install limit 
switches on the mechanism of some motor 
drives such as the arm elbow motor. The 
limit switches are normally closed 

July/August 1983 c SYNC 



Figure 6. 5 Volt DPDT Relays (16 total). 



NC 



NO 



Coil 



Common 



/V 



> 



+ 12V 



«^i" 



NC 



NO 



Coil 



Common 



+^"" 



+5V in 
(17)** 



+5Vin 
(20)* 



*hdH 



Dl 



+ 12V 
D3 

•■HI-W- 

-•■II — I r- 

C2 



"'H^>i 



Dl 



CI 



■"IHd 1 



+ 12V 


out 


(V**) 


Dl 


1N4002 


D2 


1N4148 


D3 


1N5401 


CI 


.01 MFD 25V 


C2 


22 MFD 35V 



CI 



+ 12V out 

w 

NC = Normally closed contact. 
NO = Normally open contact. 

♦Wired to this connector if relay #1. 
♦•Wired to this connector if relay #2. 



contact microswitches. A simple but ef- 
fective limit switch circuit using two 
diodes and a four terminal, terminal strip 
is depicted in Figure 7. If you happen to 
get it wired backwards (50/50 chance), 
just reverse either the 12 volt input leads 
or reverse the motor output leads. 

Input Stimuli 

Before we turn to software, a few words 
about input stimuli to the input board. 
First, the input board is the same board 
that is used for output, the Zodex RX-81 
in this case. The RX-81 provides eight 
input lines and a giuund. To input a signal 
to DO, or as I refer to it, 1-1 (input line #1 
of RX-81 board #1), you just connect the 
input line to ground. 

For my robot I installed normally open 
connect microswitches to the exterior of 
the robot with spring wire extensions 
covered with foam rubber pads. The 
bumper switches include one as a front 
bumper, one as a right bumper, and one 



as a left bumper. I actually installed two 
sets of two front bumper switches each, 
one set with a spring wire horizontally 
between them and another set with a 
spring wire vertically between them. This 
arrangement gives a larger striking area if 
the robot runs head on into something. 
The obvious expansion of the input switch 
system would be the addition of other 
types of sensors such as an ultrasonic 
range measuring system, like the one from 
a Polaroid camera focusing system, avail- 
able for about $130. 

An alternate way to accept input com- 
mands lu the computer is to wire the 
external microswitches sensors as keys 
on the ZX81 keyboard. This method 
works, but it is not totally satisfactory. 
The computer can be set up to scan the 
keyboard for specific key inputs, but the 
problem arises when two keys (or micro 
switches) are closed at the same time. 
This can easily happen if the robot works 
its way into a corner and hits the front 



and side sensors together. The computer 
will not normally accept any keyboard 
input if this happens and it could even be 
seen as an illogical input and blow the 
program. 

With sensors wired to the RX-81 par- 
ailed input board a program can be writ- 
ten to accept any combination of simul- 
taneous sensor inputs at the same time, 
and recognize them. More on that in the 
software explanations. 

Writing the Software 

When your robot motors and bumper 
switches are wired up to the ZX81 com- 
puter as described, you are ready to start 
writing software to "control the world" or 
at least the world of your robot. All pro- 
grams are for 8K ROM. The second listing 
will require 16K RAM. 

The data sheet that comes with the 
RX-81 explains a few programming in- 
structions to get you started, but my pro- 
grams written for direct robot control will 
be explained in detail. All programs 
start with the line of machine language in 
the REM statement (do not forget to 
delete the first REM statement containing 

Figure 7. Limit Switch Hookup. 



To limit 
switch 



To limit 
switch 



Dl 



£ 



/"^ 



12V 

Inputs 

from relays 



D2 

-Oh 



To motor leads 



D1,D2 1N4002 



July/August 1983 * SYNC 



25 



INTRODUCING 

EPROM SOFTWARE FOR 

TIMEX-SINCLAIR COMPUTERS 



MEMOTECH INTRODUCES THREE NEW 
SOFTWARE PACKAGES FOR YOUR 
TIMEX-SINCLAIR. 

All Memotech software is compatible with both the ZX-81 and 
TS-1000 computers and comes in its own Memopak case that plugs 
directly into your computer 

MEMOCALC 

Now there's a powerful tool to assist you with reports and financial 
forecasts. Memocalc, our spreadsheet analysis software, on EPROM, 
enables TS-1000 and ZX-81 users to perform complex number crunching 
routines with ease. With Memotech s 64K RAM a table of up to 7000 
numbers with up to 250 rows or 99 columns can be specified. Quick 
revisions can be achieved by entering new data to your formula. Then, 
by entering the command CALCULATE, the information is reevaluated 
and displayed. 

Spreadsheet analysis started as an aid to cash-flow analysis, but 
this powerful tool has now been generalized and Memocalc with it's 
special ability to perform interactive calculations is invaluable in the 
performance of numerical tasks. 

MEMOTEXT 

The Memotext word processor, on EPROM, brings commercial 
standards of text editing to your computer. Text is first arranged in 32 

character Itnoc fr>r rri£> C/raan niitK wmnMlinncJim n Ai*i^ n &*«ilUi~* /%- 
«... »...,,„ .*,» "'V uwiwwi ruwi vvinj/n,iiv,iujtv VUllltlf, 1ULU1UW. V/1I 

output the user simply chooses the line length for printing and the 
system does the rest. Used with our Memopak printer interfaces, it 



enables output with 80 character lines, upper and lower case, and single 
and double size characters. 

MEMOPAK ASSEMBLER 

The Memopak Assembler, on EPROM, is for those who want to roll 
up their software sleeves and get down to controlling precisely the power 
of their computer. It lets you code and edit a source program in the Z80 
language, and then assemble it into machine code. You can now write 
flexible and economical programs, tailor-made in every detail to your own 
needs, and free from the extravagant use of time and space that goes 
with the basic high level code. 

The editor mode allows you to code directly in the right format, 
manipulate individual lines and control the exact placing of source and 
machine code. Routines may be merged or listed (even to a commercial 
printer with our printer interfaces). 

The Assembler mode handles all standard Z80 mnemonics, 
numbers in hex or decimal, comments and user-selected labels. Be an 
expert software engineer through this pack and its clear documentation. 

ORDER AT NO RISK. 

All Memotech products earn' our 10 day money back guarantee. If 
you're not completely satisfied, return it within ten days and we will give 
you a full refund. And every Memotech product comes with a six month 
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return it to us and we will repair or replace it free of charge. Dealer 
inquiries WciCGuic. To uiuci any memuiGui product use die order 
coupon or call our toll-free number 800/662-0949, 

TS-10OO is a registered trademark of Timex Corp. 



FROM MEMOTECH . . . THE WORLD'S LARGEST 

SUPPLIER OF ADD-ON PRODUCTS FOR 

TIMEX COMPUTERS 



r 

i Mail To: Memotech Corporation, 7550 West Vale Ave . Denver, (X) 80227 

SY-78 qk 


Total 


Memocalc 


1 Memotext 49 4^ 


1 Memopak Assembler *9 9^ 


, Shipping and Handling 4.95 


$495 


1 T;l\ (Colorado residents only) 


TOTAL 


$ 


j *All price, quoted In I S dollars Price, aiui specifications subject to change without notice 

MasterCard Visa 


1 ) 


1 Vune Phoi* number 


| Vitro* 


suit 
1 





TIMEX MAKES THE 

COMPUTER, 

BUT WE MAKE IT TICK. 

If you own a TS-1000 or ZX-81 computer and want to bring out the power within it, you'll want Memotech. From easier input to high 
quality output and greater memory, Memotech makes the add-ons you demand. Even' Memotech peripheral ^--**mWl 

comes in a black anodized aluminum case and is designed to fit together in "piggy back" fashion enabling you ^i^jlll 

to continue to add on and still keep an integrated system look. 





Printer Interface " 
High Resolution Graphics 




MEMOPAK RAM All Memopak RAMs are directly addressable, user transparent, are neither switched nor 
paged and no additional power supply is required. You can also choose the Memopak RAM which is just 
right for your needs. From economy to power. 16K RAM The Memopak l6K RAM is the most 
economical way to add memory to your TS-1000. It is fully compatible with the Timex or Memotech l6K 
RAMs to provide you with up to 32K of RAM. The 16K RAM also offers additional add-on capabilities 
through its "piggy back" connection. 32K RAM The 322K Memopak enables you to execute 
sophisticated programs and store large data bases and like the 16K RAM is fully compatible with Timex's or 
Memotechs 16K RAMs to give you a full 48K of RAM. 64K RAM The 64K Memopak is powerful 
enough to turn your TS-1000 into a computer with capabilities suitable for business and educational use. It 
accepts such BASIC commands as 10 DIM A (9000). MEMOCALC Memocalc, our spreadsheet analysis 
software, enables TS-1000 users to perform complex number crunching routines with ease. With 
the 64K RAM a table of up to 7000 numbers with up to 250 rows or 99 columns can be specified. 
Quick revisions can be achieved by entering new data to your formula. 
MEMOTECH KEYBOARD For ease of operation, the Memotech keyboard is a high quality 
standard typewriter keyboard, with TS-1000 legends. The keyboard is cable connected to a buffered 
interface which is housed in a standard Memopak case and plugs directly into the back of the 

TS-1000 or other Memopaks. MEMOPAK HRG The Memopak High Resolution Graphics, with 
up to 192 by 248 pixel resolution, enables display of high resolution "arcade game" style graphics 
through its resident 2K EPROM, programmed with a full range of graphics subroutines. 
CENTRONICS PARALLEL AND RS232 INTERFACES 
Memotech's Interfaces enable your TS-1000 to use a wide range of 
compatible printers. The resident software in the units gives the 
complete ASCII set of characters. Both Memopak Interfaces provide lower case character capabilities and 
up to 80 column printing. The RS232 Interface is also compatible with modems and terminals. 
SEIKOSHA GP IOOA PRINTER The Seikosha GP 100A uses a 5x7 dot matrix printing format with 
ASCII standard upper and lower case character set. Printing speed is 30 characters/second with a 
maximum width of 80 characters. The printer uses standard fanfold paper up to 
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interface. Other printer packages are also 
available through Memotech. 
ORDER AT NO RISK. All Memotech 
products carry our 10 day money back 
guarantee. If you're not completely 
satisfied, return it within ten days and we 
will give you a full refund. And every 
Memotech product comes with a six 
month warranty. Should anything be 
defective with your Memotech product, return it to us and we will repair or replace 
it free of charge. Dealer inquiries welcome. To order any Memotech product use 
the order coupon or call our toll-free number 800/662-0949. 

TS-1000 li a registered trademark of Timex (x>rp 






i i^L = JUi\.l.iJ 

CORPORATION 



7550 tet Vale Avenue, Denver, Colorado 802.T, m 986-1516, TO 910-320-2917 



Mail To: Memotech Corporation. 7550 Wed Yale Ave . Denver. 00 90227 
SY " 78 <h 


| 16K RAM 


t 4995 




| J2KRAM 


9995 




| twK RAM 


14995 




| Memocak 


4995 




■ kexhoard with Interface 


9995 




1 High Resolution Graphics 


9995 




■ i-tniromo. Parallel Interface 


74.95 




, RS232 Info 


9995 






1995 






39900 




1 shipping and Handling 


495 


M.95 | 


1 lax (Colorado reside 


1 inixi. 




* 1 


1 *. Ml prices quoted in 1 S dollar. '•' 
| ** please add an addition.* v 


to chanise without noUce | 


< 


1 Name 
| 




Phone number ■ 








state Zip 1 



.-I 



Function 


Body 


left 


Body 


right 


t... wh 


fwd 


L wh 


rev 


R wh 


fwd 


R wh 


rev 


L sh 


dr. 


L sh 


up 


R sh 


dn 


R sh 


up 


L el 


dr. 



Figure 8. Software Commands. 



!... el up 

R el up 

R el dn 

R hand close 

R hand open 



Relay 

1. 


4 


5 


6 


9 


10 


11 


12 


15 


16 


17 


18 


19 


20 



Switch 

Front bumper 
Left bumper 
Ri ght bumper 

Right palm 
(Note: A = 16522 and B = 16524) 





Output 


POKE A. 


POKEB 




1 -5 


16 


7 




1 -6 


«y ,_. ( 


7 




1-1 


I 


7 




1-2 


2 


7 




1 -3 


4 


7 




1-4 


8 


7 




2-1 


1 


6 




2—2 


7 


6 




*■> ■? 


4 


6 




2-4 


8 


6 




2-5 


16 


6 




2-6 


7;~ 


6 




2-7 


64 


6 




2-8 


128 


6 




1-7 


64 


7 




1-8 


128 


7 


Input 


1FIN- 


POKE B, 


i-i 


1 




7 


1-2 


'-I, 




7 


1-3 


4 




7 


1 


-8 


12 


8 




7 



LET YOUR ZX81/TIMEX 1000 WORK FOR YOU!! 

PERSONAL AND BUSINESS PROGRAMS: 

Are on cassette, are menu driven, run with or without a printer and save on tape automatically. 

SALES r,LE3 >•* or ™v: nous \mm 16K) (600 64K} products w wholesale and retail pnces. - Shows separate wholesale 
and retail totals and amount of profit in up to (25 16K) (10O64K) different accounts. - Records inventory automatically or 
manually - Totals sates tax - Cash register mode totals, identifies, adds sales tax, and keeps records for your bookkeep.no 
Pnnts a list of products, accounts, inventory and sales slips with pnnter. 
*" A must for any small business '" $19 95 

CHECKING 16K or 64K: Lists (25/100 (KXV64K) deposits showing amount and date entered - Lists (8016K) (500/64K) 
checks and displays check number, date and payee - Lists by account total of checks written. Keeps running total of checks 
written and balance left in account - Adds interest and subtracts service charges. - Search tor a check by number name 
date or amount - Pnnt a list of deposits, accounts, and checks with pnnter 

— Great for tax records '" $9 95 

INVENTORY 16K or MK: May be used for everything from keeping an accurate inventory for your business to your persona! 
recora collection - Holds up to (150 16K {750 64K) items w comments for each. - Comments may be used foTsenal 
numbers dates, pnces or location. - List all items, search tor single item, change or delete any item. - Sort items m 
alphabetical or numencal order. — Prints a list of items, quantities and comments. 
"■ Everyone should have an inventory of household rtems in case of fire or theft. '" . $9 95 

MAILING UST 1SK or 64K: Holds (100 16K) (425 64K) names, addresses and telephone numbers - Search by name aty 

zip code, or phone number - Will sort by name. city, or zip code in alphabetical or numerical order - Lists all names' 

changes or deletes - Pnnts list of names or names and addresses or address labels it they are available for your pnnter ' 

A valuable tool tor your home or business"' $9 95 

APPOINTMENT CALENDAR 16K: May be used for everything from reminding you of birthdays to business appointments 

— Just enter the date and list up to (8) appointments per day for up to (31 ) days - Lets you change or delete any appointment 

— Pnnt a list of appointments for day or month - Save all appointments on tape 
**' Keep a permanent record of past appointments *" 



$9 95 



Send for free catalog of personal, business and educational programs 



Any three $9.95 tapes for $24.95 
Add $1 .00 per tape for shipping 
Indiana residents add 5% sales tax. 
Send Cert. Check, MO. , Visa or 
MasterCard No. w/Exp. Date 



DEALER INQUIRIES INVITED 

HEATH COMPUTER SERVICES 

950 East -52 South 
Greentown, IN 46936 
Phone 31 7-628-31 30 



28 



the program name before running the 
program) followed by POKE 16517, 79. 

To activate an output line you first 
POKE the binary number for the line, 
then POKE the number of the output 
board (if you have more than one board) 
and the activate the command with an 
OUT USR statement. For example, if you 
wanted to activate output line #3 on an 
output board wired as "OUT T you would 
write the program as follows: 

100 POKE 16522,4 
(addresses line #3) 

110 POKE 16524,7 
(addresses board wired as OUT 7) 

120LETOUT=USR 16521 
(activates command) 

As listed in Figure 8, this would make 
the right wheel move the robot forward. 
To make the right and left wheels go 
forward use the following lines: 

130 POKE 16522,5 
(addresses line #1 and #3 together by 
adding their binary numbers 1 4- 4) 

140 POKE 16524,7 
(addresses board wired as OUT 7) 

150 LET OUT=USR 16521 
(activates command) 

To turn these motors off, POKE 0, as 
follows: 

160 POKE 16522,0 
(deactivates all output lines) 

170 POKE 16524,7 
(addresses board wired as OUT 7) 

180 LET OUT=USR 16521 
(activates command) 

Memory Saving Shortcuts 

As you might have gathered from Fig- 
ure 8, there are some memory saving 
shortcuts to this programming. If you add 
the following LET statements earlier in 
the program, you save memory and make 
the program statements easier to type 
into the computer. 

10 LET A= 16522 

20 LET B= 16524 

30 LET C= 16521 

The above lines 100-180 can now be 
shortened to: 

100 POKE A,4 

110 POKE B/7 

12QLETOUT=USRC 

130 POKE A,5 

140 POKE B/7 

150 LET OUT = USR C 

160 POKE A,0 

170 POKE B,7 

180LETOUT=USRC 

Other refinements are possible to 
further save program steps. For example, 
lines 140 and 170 can be omitted because 
location B (16524) remains POKEd 
throughout the sequence. If you change 
from the OUT 7 board to a second board 
wired as OUT 6 and back again, the 
POKE 16524 step would have to be in- 
cluded each time so that the proper board 
would be addressed. 

July/August 1 983 e SYNC 



IM0W.ATS1000/ZX81 

PUSH-BUTTON 

KEYBOARD 

FOR UNDER $20.00. 




At last there's a really cheap but 
efficient way of ironing out theTS1000/ZX8Ts 
only real bug: its keyboard. The Filesixty 
Buttonset offers 

■ A full -travel calculator-type moving 
keyboard for only $19.50. 

■ Installed in seconds. The peel -off 
adhesive backing means you just register into 
position and press. 

■ No messy labels, dismantling or 
soldering. 

■ 3 groups of colour keys to pick out 
shift, numerals and newline. 

■ Precision moulded in ABS to match 
your TS1000/ZX81, with contrasting legends 
for maximum legibility. 

Orders to Filesixty Ltd., 25 Chippenham Mews, London W9 2AN, 
England. Tel: 01-289 3059. Telex: 268 048 EXTLDN G 4087. 



^^2 




.re the original ki 



So all you do is remove the 
protei • 



_ 



2 The Buttons*- 



4. And place it centrally on your TS1000/ ZX81 



Cheques/money orders made payable to Filesixty Ltd. 



Please send me_ 



(qty.) Buttonset(s) 



at $19 50 parh (inclusive of postage & packaging) 
Total $_ 



BLOCK CAPITALS 



Name. 



(U.S. DOLLARS ONLY) 



Address. 



State 

Zip 



.ESiXTY 



Parts List 

(Parts with common part numbers have 
been omitted from this list, i.e., trans- 
istors, ICs and resistors) 

Power Supply 

2300 MFD, 33VDC capacitor. Jam- 
eco n 2300@33V, 

5k ohm adjustable pot (10 turn). 
Mouser # 593-830P. 

125 uH, 3.5 amp Hash Choke. 
Mouser # 542-5252. 

DIP Relay Board 

5vBIP relay. Mouser* 518-5002105. 
PC board. Hobby board. Digi-key # 
K160-ND. 

5 volt DPDT relay board 

5v DPDT relay. All Electronics ft 
FRLY-6. 

PC board (Same as DIP relay board 
above). 

Transistor switch board 

PC board (same as PC board above). 



Circuit board holder 

Edgeboard connectors. Digi-key C 1 - 



22. 



Intermediates connector (Photo 2) 
PC board (same as PC board above). 
Edgeboard connectors (one con- 
nector can be cut into the size shown). 
Digi-key n C5-50. 

Computer Continuum expansion 
board 

If the bare board is purchased, a 
parts list is provided, 

Zodex RX-8I 

If the bare board is purchased, a 
parts list is provided. 

Addresses: 

Jameco Electronics, 1355 Shoreway 
Road, Belmont, CA 94002. 

Mouser Electronics, 11433 Wood- 
side Ave., Santee, CA 92071. 

Digi-key Corporation, P.O. Box 677, 
Thief River Falls, MN 56701. 

All Electronics Corp., P.O. Box 
20406, Los Angeles, CA 90006. 

Computer Continuum, 301-16 Ave., 
San Francisco, CA 94118. 

ZODEX, East Hill, Oakham, MA 
01068. 



Test Program 

An example of a test program is pro- 
vided in Listing 1. This program activates 
a single output line and then stops. If you 
enter CONT, it will then turn the output 
line off and stop again. Enter CONT, and 
it will activate the next output line and so 
forth, repeating the process. 

The input line activation is a little 
simpler. You first ready the input for 
activation and then use IF statements to 
look for the proper input to activate a 
response. For example: 

500 LET IN=USR 16514 
(readies input for activation) 

510 IF IN= 1 THEN GOTO 100 
(if input line #1 is activated, the program 
jumps to line 100) 

If more than one input board is used, a 
POKE 16524 line would have to precede 
the USR line to identify the board in 
accordance with how it is wired. In my 
robot only one board is used for input as 
eight input lines are more than enough. 
Also, the same memory saving techniques 
can be used 

LETF=16514 

A sample routine to scan for inputs is 
as follows: 

900LETIN=USRF 

910 IF IN= 1 THEN GOTO 100 

920 IF IN=2 THEN GOTO 200 

930 IF IN=4 THEN GOTO 300 

940 GOTO 900 



Robotics Note 

The Radio-Electronics series on build- 
ing a robot is available in reprint form for 
$12 plus $1 s&h from: Radio-Electronics, 
Reprint Dept., 200 Park Ave. South, New 
York, NY 10003. Readers who want to 
communicate with the author Bruce 
Taylor may do so in care of SYNC. 



1 


REM "RX61" 






2 


REM < =* J + TftN Y PEEK /TRN 


10 


POKE 16517,79 




20 


LET fi= 16522 






30 


LET B = 16524- 






4-0 


LET C=1652i 






50 


POKE R . 1 






60 


POKE B.6 






70 


LETOUT^USP 


C 












90 


GOSUB 530 






100 


STOP 






110 


POKE R,2 






120 


POKE 6,6 






130 


LET QUT=USR 


c 




14-0 


STOP 






150 


GOSUB 530 






160 


STOP 






170 


POKE R.4. 






130 


POKE B,6 






190 


LET OUT=USR 


c 




200 


STOP 






210 


GOSUB 530 






220 


STOP 






230 


POKE R,8 






24-0 


POKE B , 6 






250 


LET OUT=U5R 


Q 




260 


STOP 






270 


GOSUB 530 






280 


STOP 






290 


POKE R, 16 






300 


POKE B , 7 






310 


LET OUT=USR 


c 




320 


STOP 






330 


GOSUB 570 






34-0 


STOP 






350 


POKE R,32 






360 


POKE B,7 






370 


LET OUT=USR 


c 




380 


STOP 






390 


GOSUB 570 






4-00 


STOP 






4-10 


POKE R,64. 






4.20 


POKE B,7 






4.30 


LET OUT^USR 


c 




4-40 


STOP 






450 


GOSUB 570 






460 


STOP 






4-70 


POKE R. 128 






4-80 


POKE B,7 






4-90 


LET OUT=U5R 


c 




500 


STOP 






510 


GOSUB 570 






520 


STOP 






530 


POKE R . 






540 


POKE B.6 






550 


LET OUT=USR 


c 




560 


RETURN 






570 


POKE R.0 






560 


POKE B.7 






590 


LET OUT=USR 


c 




600 


RETURN 







Program to Move the Robot Forward 

Listing 2 is a portion of the program 
that is currently in my robot. It moves the 
robot forward (R + L wheel fwd), while 
scanning for hits on the microswitch sen- 
sors in the form of inputs. If the right 
bumper input is activated, the robot stops 
its forward motion, backs up, turns to the 
left about 30 degrees and continues for- 
ward, again sensing for bumper inputs. 
The sequence is similar for a left bumper 
input except that it turns to the right 
about 30 degrees before continuing. 

The sequence for a front bumper hit is 
a little different in that a random number 
generator is used so that 50* of the time 
the robot turns right 60 degrees and 50* 
of the time it turns left 60 degrees before 
continuing forward. A counting step is 
also included as part of the input scanning 
routine so that the robot moves forward 
for about nine seconds and then generates 
a random number between zero and one. 
One third of the time it will stop and go 
into a body rotating and arm demon- 
stration subroutine. 

Timing Techniques 

Several timing techniques are used in 
the program. PAUSE is a good technique 
when interruption is not required such as 
in arm movements, where there is no 
danger of hitting or running into some- 
thing. The FOR-NEXT loop is a good 
technique for input scanning when there 
is a possibility of a collision with another 
object. A counting technique as a loop 
also works well in this situation. 

The Expansion Boards 

Do not be scared off by this project if 
you are not willing to go the full expansion 
route with a board such as the Computer 
Continuum product. The Computer Con- 
tinuum expansion board was chosen be- 
cause of its 3 amp capacity for 5 volt 
supply as additional circuits are added to 
the robot. 

The Zodex RX-81 board (also available 
assembled as a "Control Board for 8 
devices") can be plugged directly into the 
ZX81 bus just as the printer and 16K 
RAM are plugged in. If you want to add 
more boards, a simple Y connector will 
do the trick. 

However, if you want to use the Com- 
puter Continuum expansion board, you 
must know which of the two versions of 
the board you have, neither of which can 
be used as I have described without some 
modification. The earlier version of the 
board will accept the Zodex board plug- 
ged directly into an expansion edge con- 
nector (50 pin, .1 inch centers) soldered 
to the CC board, but the logic will not 
work without an additional simple de- 
coder circuit you will have to build. The 
Sinclair printer will not work without this 
decoder circuit either. 



30 



July/August 1983 c SYNC 



The newer version of the CC expansion 
board comes with the decoder circuit 
built into the board, but the expansion 
pad pinout has been reversed so that the 
Zodex board can no longer be plugged 



directly onto the CC board. The Zodex 
board can be plugged onto the bus con- 
nection for the 16K RAM, but then you 
have to work out another location for the 
RAM. 



Listing 2. 



2 REM 'k™* 1 * TfiN Y PEEK riRN 

10 POKE 1651?.. "79 

20 GOTO 2060 

30 POKE R,0 

4-0 POKE B,7 

50 LET OUT=U5R C 

&0 PAUSE 30 

70 POKE ft.. 10 

80 GOSUB E 

90 PAUSE 70 

100 GOSUB D 

110 IF RND<«5 THEN GOTO 14-0 

120 POKE ft, 6 

130 GOTO 135 

140 POKE ft, 9 

1S0 GOSUB E 

160 PAUSE 37 

170 GOSUB D 

180 GOTO 3210 

190 POKE R.0 

200 LET OUT=USR C 

210 PAUSE 30 

220 RETURN 

230 LET OUT=USR C 

24-0 RETURN 

250 POKE fi,0 

2S0 POKE B,7 

270 LET OUT=USR C 

280 PAUSE 30 

290 POKE ft, 10 

300 GOSUB E 

310 PAUSE 37 

320 GOSUB D 

330 POKE ft, 9 

340 GOSUB E 

350 PAUSE 5 

380 GOSUB D 

370 GOTO 2210 

380 POKE ft,0 

390 POKE B,7 

4-0© LET OUT=U5R C 

410 PAUSE 30 

420 POKE ft, 10 

430 GOSUB E 

440 PAUSE 37 

450 GOSUB D 

480 POKE ft, 6 

4-70 GOSUB E 

480 PAUSE 5 

490 GOSUB D 

500 GOTO 2210 

510 STOP 

520 REM RANDOM SELECT 

530 IF RMD < . B? THEN GOTO 2250 

540 POKE A,© 

550 POKE B..7 

560 GOSUB E 

570 POKE A, 10 

580 GOSUB E 

590 PAUSE 100 

600 POKE A,0 

610 GOSUB E 

620 POKE A. 9 

630 GOSUB E 

640 PAUSE 37 

650 POKE A.0 

660 GOSUB E 

670 POKE A, 5 

680 GOSUB G 

650 FOR U=l TO 12 

700 LET IN=USR F 

710 IF IN =4 THEN GOTO 760 

720 IF IN=1 THEN GOTO 760 

730 IF IN = 5 THEN GOTO 760 

740 IF U=12 THEN GOTO 780 

750 NEXT U 

760 GOSUB D 

770 GOTO 380 

780 GOSUB D 

790 POKE ft, 10 

300 GOSUB G 

810 FOR U = l TO 20 

820 IF U=20 THEN GOTO 840 

830 NEXT U 

84-0 GOSUB D 

850 POKE A, 6 

860 GOSUB E 

870 PAUSE 90 

880 POKE A.,0 

890 GOSUB E 

900 POKE A, 5 

910 GOSUB G 

920 FOR U=l TO 12 

930 LET IN=USR F 

94-0 IF IN=2 THEN GOTO 990 

950 IF IN = 1 THEN GOTO 990 

960 IF IN =3 THEN GOTO 990 

370 IF U=12 THEN GOTO 1010 

980 NEXT U 

990 GOSUB D 

3 000 GOTO 250 

1010 GOSUB D 

1020 POKE A, 10 

1030 GOSUB G 

1040 FOR U=l TO IB 

1050 IF U=18 THEN GOTO 1070 

1060 NEXT U 

1070 GOSUB D 

1080 POKE ft, 9 

1090 GOSUB E 

1100 PAUSE 37 

1110 POKE ft,0 

1120 POKE B,7 

1130 GOSUB E 

1140 POKE A. 32 

1150 POKE B.7 

1160 GOSUB G 



1170 
1180 
1190 
1200 
1210 
1220 
1230 
1240 
1250 
1260 
1270 
1280 
1290 
13CI0 
1310 
1320 
1330 
134-0 
1350 
1360 
1370 
1360 
1390 
1400 
14-10 
1420 
1430 
1440 
14-50 
1460 
1470 
14-80 
14-90 
1500 
1510 
1520 
1530 
154.0 
1550 
1560 
1570 
1580 
1590 
1600 
1610 
1620 
1630 
164 
1650 
1660 
1670 
1680 
1690 
1700 
1713 
1720 
1730 
174-0 
1750 
1760 
1770 
1780 
1790 
1800 
1810 
I82S 
1830 
iS40 
1850 
i860 
1870 
1880 
1890 
1900 
1910 
1920 
1930 
194.0 
1950 
I960 
1970 
1980 
1990 
2000 

2010 

5020 
2030 
2040 
•050 
-■06 
2070 
2080 
2090 
2100 
2110 
2120 
2130 
214-0 
2150 
2160 
2170 
2180 
2190 
2200 
2210 
,^220 
2230 
224 
2250 
2260 
2270 
2280 
2290 
2300 
2310 
2320 
2330 
234-0 



PAUSE 80 

GOSUB D 

POKE R, 16 

GOSUB E 

PAUSE 130 

GOSUB D 

POKE A, 32 , 

GOSUB E 

PAUSE 45 

GOSUB D 

POKE ft, 14-4 

GOSUB E 

POKE A, 18 

GOSUB G 

PAUSE 30 

POKE ft, 154 

GOSUB E 

PAUSE 20 

GOSUB D 

POKE ft, 128 

POKE B,7 

GOSUB E 

PAUSE 70 

GOSUB D 

FOR U=l TO 300 

LET IN=USR F 

IF IN =128 THEN GOTO 1460 

IF U=300 THEN GOTO 14.60 

NEXT U 

POKE ft, 6* 

POKE B, 7 

GOSUB E 

POKE A . 96 

POKE B,6 

GOSUB E 

PAUSE 50 

POKE ft, 33 

GOSUB G 

PAUSE 10 

POKE ft, 97 

GOSUB E 

PAUSE 5 

GOSUB D 

POKE ft , 70 

POKE B,7 

GOSUB G 

PRUSE 230 

POKE A, 64 

GOSUB E 

POKE ft , 69 

GOSUB G 

PAUSE 260 

POKE ft, 64 

GOSUB E 

POKE ft . 144 

POKE 5,6 

GOSUB E 

POKE ft, 16 

GOSUB G 

PAUSE 10 

POKE ft.. 14-6 

GOSUB E 

PAUSE 20 

GOSUB D 

LET IN=USR F 

IF IN=0 THEN GOTO 164-0 

PAUSE 40© 

POKE ft . 126 

POKE B . 7 

GOSUB E 

POKE ft . 96 

POKE B,6 

GOSUB E 

PAUSE 100 

POKE ft. 33 

GOSUB G 

PAUSE 10 

POKE ft, 101 

GOSUB E 

GOSUB D 

POKE ft, 64 

POKE B,7 

GOSUB E 

PAUSE 40 

POKE ft, 6 

GOSUB G 

PRUSE 230 

GOSUB D 

GOTO 2210 

LET ft =16533 
B= 16524 
C= 16521 

LET D=190 

LET E=200 

LET F=16514 

LET G=230 

POKE ft,0 

POKE 5,7 

LET OUT-USR C 

POKE A,0 

POKE B,6 

LET OUT=USR C 

PAUSE 400 

LET RN= 1 

POKE A. 5 

POKE B . 7 

LET OUT=USR C 

LET TN=0 

LET TN=TN+1 

LET IN=USR F 
IF IN=1 THEN GOTO 30 
IF IN=2 THEN GOTO 250 
IF IN=4 THEN GOTO 360 
IF IN =3 THEN GOTO 250 
IF IN=5 THEN GOTO 380 
IF IN=7 THEN GOTO 30 
IF TN=20 THEN GOTO 530 

GOTO 2250 



LET 
LET 



July/August 1 983 c SYNC 



The easiest way to tell the two versions 
of the CC board apart is that the newer 
version has a 74LS27 IC chip located next 
to the optional LM323 voltage regulator 
while the older version does not. By the 
way, I highly recommend using the op- 
tional voltage regulator, because it lets 
you bypass the voltage regulator in the 
ZX81 and you can kiss overheating prob- 
lems goodby forever. 

If you have the older version you can 
plug the Zodex board directly onto an 
edge connector on the CC board. Al- 
though there are several ways to install 
the required decoder circuit, I recom- 
mend writing to Computer Continuum 
and asking for a copy of the documen- 
tation sheet for the new version. Figure 1, 
schematic, and Figure 2, legend, is all you 
will need. Then install the 74LS27 just as 
it is installed on the new version. It can 
be installed in the same spot as the new 
version with an IC socket, a few jumper 
wires, and some cuts in the circuit board 
foil. If you do this, you have essentially 
the newer version. 

If you have the newer version of the 
Computer Continuum board, the decoder 
is already installed. If you do not want to 
solder the Zodex board(s) directly to- 
gether, you will have to build an inter- 
mediate connector. One solution is shown 
in Photo 1. The pinouts of the .1 inch 
center edge connectors are jumpered to 
the correct fingers of the .156 inch center, 
4x5 inch PC board. 

Robot Expansion Plans 

I hope I have helped you get started 
in a robot project. If you are serious about 
a self-contained robot, I recommend the 
Radio-Electronics robot reprint articles 
as a source of much useful information. 
The whole idea of this project to inter- 
nally control a robot with a ZX81 com- 
puter is to demonstrate how much power 
the little computer really has. I have not 
yet maxed out the 16K RAM, although I 
am ready with a 16K Byte-Back module 
to add to the Sinclair 16K RAM pack. 

Future robot expansion plans include 
measurement of robot movements and 
feedback of this information into the com- 
puter memory so that the robot can learn 
as it moves about and functions. A digital 
voice and voice recognition circuit is also 
possible since these circuits are becoming 
available in the $50-150 range. The ZX81 
can be expanded to do an almost iimitiess 
number of functions without great cost. 

And finally, even if you go with a full- 
blown robot project, you do not have to 
sacrifice your ZX81 or TS1000 to dedi- 
cated robot control. A keyboard plug and 
an extension of the video plug have been 
added to my ZX81 in the robot. The 
robot can stop and perform as a regular 
computer by simply plugging in an ex- 
ternal keyboard and video display. H 

31 



So You Wished You Had Bought A TS2000 

Daniel G. Roy 



The Challenge of the TS2000 

How would you like to have a computer with a color video 
display of fifteen colors, quality sound, high resolution, 
unlimited character sets, and a dual joystick interface? How 
would you like a system in which you do not have to worry 
about expansion? If you have a ZX81 (or ZX80 with the 8K 
ROM), you could have such a system-the COLORSIN8L 

Since ZX81 hardware and software are incompatible with 
the TS2000 expansion bus, many of us who have made sizeable 
investments in these items will not be able to justify purchasing 
the new product, as is the case with me. 

This article sets forth my answer to the challenge of the 
TS2000 in a design to give the ZX81 the capability of having 
all of these features at a very reasonable cost. We will cover 
the system features, circuitry background, applications, con- 
struction of the board, testing and debugging, and program- 
ming. Many of the debugging suggestions are useful in other 
applications. 

System Features 

Most peripherals on the secondary market provide the user 
with a new capability or function. They normally are not 
designed or sold to be interactive with the user or the machine. 
This system has been designed differently; it has the user in 
mind. By building or purchasing this system, you are not only 
adding the features mentioned, but are actually opening your 
system to be anything that you want it to be. 

Figure 1 compares the COLORSIN81 with the TS200G in 
features, ease of use, and expandibility. 

The two systems use entirely different approaches in cre- 
ating their displays. The TS2000 uses a new ULA to produce 
color, with the high resolution being a product of new software. 
The COLORSIN81 uses a dedicated IC to produce and 
maintain a display. It requires none of the user memory! It 
has its own 16K of video memory to store images and pages 
in. As you will see later, this protected memory has many 
other uses. 

The 6-slot motherboard includes two slots which will accept 
Radio Shack stocked boards. For interfacing your homebrew 
circuits to the Sinclair I have included 8 memory-mapped 
select lines. These are for the exclusive use of experimenters 
and hobbyists. 

Daniel G. Roy, 99 Andover St., Lawrence, MA 01843. 
32 



So that the user does not have to "call" the capabilities of 
the board when required, the computer jumps to the system 
PROM, does the initialization of the system, loads the color 
display into memory, enables the sound, checks for joystick 
activity, and prompts the user with a "ready'' on the screen. 

Because the system PROM does the initialization, 64K 
RAM packs are fully supported. POKEing the Sinclair 
RAMTOP variables to have access to the upper half of 
memory is not necessary. 

Since this system does not depend on the Sinclair to 
maintain a display, the computer may be run exclusively in 
the FAST mode. However, if you want both displays at the 
same time, you could run the system in the SLOW mode and 
use two TVs. 

Figure 1. Comparison of COLORSIN81 and TS2000 Features. 



Number of colors available 

Maximum pixel resolution 
Sound range (octaves) 
Sound produced by: 

Number of joysticks 
Characters/line 
Ram available to user 

Additional video ram 
Program merging supported 
Sprites available to user 
User definable characters 
Character sets redefinable 
Expansion slots provided 
Interface circuitry provided 



New Commands 

The system adds 17 new commands (see Figure 2), including 
READ, DATA, and RESTORE. However, after you discover 
the power of the other commands, you will consider these to 
be less important. 

You will now be able to MERGE and CHAIN programs, 
whether in Basic or machine language. Instead of writing 

July/August 1 983 c SYNC 



COLORSIN81 


TS2000 


15 + 


8 


transparent 




256 X 192 


256 X 192 


8 


10 


speaker 


piezoelectric 




element 


2(4) 


N/A 


32-40 


32 


56K 


48K less 




display 


16K 


N/A 


yes 


no 


32 


N/A 


256-768 


21 


yes 


no 


6 


1 (the bus) 


8 select lines 


N/A 



AARDVARK - THE ADVENTURE PLACE 
TRS-80 COLOR COMMODORE 24 VIC-20 SiNCLAIR/TIMEX TI99 



WE CARRY MORE THAN ADVENTURES!! 

MAXI PROS WORD PROCESSING \&** 

The easiest to use word processor that ! 
know of. Has all the features of a major word 
processor (right and left margin justification, 
page numbering, global and line editing, single, 
double, triple spacing, text centering, etc.) at 
a very cheap price because we wrote it in 
BASIC. Includes 40 page manual and learning 
guide. Easily modified to handle almost any 
printer combination. Available on disk or tape 
for VIC20, COMMODORE64, and TRS-80 
COLOR computer. Requires 13k RAM on 
Vic, 16k EXTENDED on TRS-80 COLOR. ^ 
$19.95 on tape $24.95 on disk. rffc 

GENERAL LEDGER - Complete bookkeep- 
ing for a small business. Disk required. For 
Vic20 (13k), Commodore64, TRS-80 COLOR 
(16k EXTENDED). $69.95 (Send $1.00 for 
manual before ordering.) 



( 



LABYRINTH - 16K EXTENDED COLOR 
BASIC - With amazing 3D graphics, you fight 
your way through a maze facing real time 
monsters. The graphics are real enough to 
cause claustrophobia. 

Similar game for Timex/Sinclair 16k - hunting 
treasure instead of monsters $14.95. 




ADVENTURE WRITING/DEATHSHIP by 
Rodger Olsen - This is a data sheet showing 
how we do it. It is about 14 pages of detailed 
instructions how to write your own adven- 
tures. It contains the entire text of Deathship. 
Data sheet - $3.95. NOTE: Owners of TI99, 
TRS-80, TRS-80 Color, and Vic 20 computers 
can also get Deathship on tape for an addi- 
tional $5.00. 

Dealers- We have the best deal going for you. 
Good discounts, exchange programs, and fac- 
tory support. Send for Dealer Information. 
Authors- Aardvark pays the highest commis- 
sions in the industry and gives programs the 
widest possible advertising coverage. Send a 
Self Addressed Stamped Envelope for our 
Authors Information Package. 



ADVENTURES - Adventures are a unique 
form of computer game. They let you spend 
30 to 70 hours exploring and conquering a 
world you have never seen before. There is 
little or no luck in Adventuring. The rewards 
are for creative thinking, courage, and wise 
gambling not fast reflexes. 

In Adventuring, the computer speaks and 
listens to plain English. No prior knowledge 
of computers, special controls, or games is re- 
quired so everyone enjoys them — even people 
who do not like computers. 

Except for Quest, itself unique among Ad- 
venture games, Adventures are non-graphic. 
Adventures are more like a novel than a comic 
book or arcade game. It is like reading a par- 
ticular exciting book where you are the main 
character. 

All of the Adventures in this ad are in Basic. 
They are full featured, fully plotted adventures 
that will take a minimum of thirty hours (in 
several sittings) to play. 

Adventuring requires 16k on Sinclair, TRS- 
80, and TRS-80 Color. They require 8k on OSI 
and 13k on VIC-20. Sinclair requires extended 
BASIC. Now available for TI99. 

TREK ADVENTURE by Bob Retelle - This 

one takes place aboard a familiar starship and 
is a must for trekkies. The problem is a famil- 
iar one - The ship is in a "decaying orbit" 
(the Captain -never could learn to park!) and 
the engines are out (You would think that in 
all those years, they would have learned to 
build some that didn't die once a week). Your 
options are to start the engine, save the ship, 
get off the ship, or die. Good Luck. 

Authors note to players - I wrote this one 
with a concordance in hand. It is very accurate 
- and a lot of fun. It was nice to wander 
around the ship instead of watching it on T.V. 

DERELICT by Rodger Olsen and Bob Ander 

son For Wealth and- Glory, you have to ran- 
sack a thousand year old space ship. You'll 
have to learn to speak their language and 
operate the machinery they left behind. The 
hardest problem of all is tojive through it. 

Authors note to players - This adventure 
is the new winner in the "Toughest Adventure 
at Aardvark Sweepstakes". Our most difficult 
problem in writing the adventure was to keep 
it logical and realistic. There are no irrational 
traps and sudden senseless deaths in Derelict. 
This ship was designed to be perfectly safe for 
its' builders. It just happens to be deadly to 
alien invaders like you. 

Dungeons of Death - Just for the 16k TRS- 
80 COLOR, this is the first D&D type game 
good enough to qualify at Aardvark. This is 
serious D&D that allows 1 to 6 players to go 
on a Dragon Hunting, Monster Killing, Dun- 
geon Exploring Quest. Played on an on-screen 
map, you get a choice of race and character 
(Human, Dwarf, Soldier, Wizard, etc.), a 
chance to grow from game to game, and a 15 
page manual. At the normal price for an Ad- 
venture ($14.95 tape, $19.95 disk), this is a 
giveaway. 



PYRAMID by Rodger Olsen This is one of 
our toughest Adventures. Average time 
through the Pyramid is 50 to 70 hours. The 
old boys who built this Pyramid did not mean 
for it to be ransacked by people like you. 

Authors note to players - This is a very 
entertaining and very tough adventure. I left 
clues everywhere but came up with some in- 
genous problems. This one has captivated 
people so much that I get calls daily from as 
far away as New Zealand and France from 
bleary eyed people who are stuck in the 
Pyramid and desperate for more clues. 

MARS by Rodger Olsen - Your ship crashed 
on the Red Planet and you have to get home. 
You will have to explore a Martian city, repair 
your ship and deal with possibly hostile aliens 
to get home again. 

Authors note to players - This is highly 
recommended as a first adventure. It is in no 
way simple-playing time normally runs from 
30 to 50 hours - but it is constructed in a 
more "open" manner to let you try out ad- 
venturing and get used to the game before 
you hit the really tough problems. 



Acst 




QUEST by Bob Retelle and Rodger Olsen - 

THIS IS DIFFERENT FROM ALL THE 
OTHER GAMES OF ADVENTURE!!!! It is 
played on a computer generated map of 
Alesia. You lead a small band of adventurers 
on a mission to conquer the Citadel of Moor- 
lock. You have to build an army and then arm 
and feed them by combat, bargaining, explora- 
tion of ruins and temples, and outright ban- 
ditry. The game takes 2 to 5 hours to play 
and is different each time. The TRS-80 Color 
version has nice visual effects and sound. Not 
available on OSI. This is the most popular 
game we have ever published. 

32K TRS 80 COLOR Version $24.95. 
Adds a second level with dungeons and 
more Questing. 

PRICE AND AVAILABILITY: 

All adventures are $14.95 on tape. Disk 
versions are available on VIC/COMMODORE 
and TRS-80 Color for $2.00 additional. $2.00 
shipping charge on each order. 



Please specify system on all orders 

ALSO FROM AARDVARK - This is only a partial list of what we carry. We have a lot of other games (particularly for the 
TRS 80 Color and OSI), business programs, blank tapes and disks and hardware. Send $1.00 for our complete catalog. 

AARDVARK 

2352 S. Commerce, Walled Lake, Ml 48088 / (313) 669-3110 ffl^ 



Phone Orders Accepted 8:00 a.m. to 4:00 p.m. EST. Mon.-Fri. 
TRS-80 COLOR TIMEX/SINCLAIR COMMODORE 64 

$2.00 shipping on each order 



VIC-20 



each program from the first line each time, just load in any 
number of subroutines and combine them with your new 
"application." Your programming speed will increase many 
times over. By "chaining," I mean that a tone could place in 
protected memory certain items of data and have this data 
shared by many other programs, each being able to change or 
modify the contents of the data. 

Files and other data structures are supported on this system 
with easier manipulation of information. You will not have to 
dimension arrays for storing data, worry about RUN or 
CLEAR destroying hours or days worth of work, or be 
concerned with managing the memory. 

You will be able to create animation easily, plot complex 
functions directly in high resolution, if desired, and easily 
interface your machine language programs with a special 
COLORS1N81 system variable which contains the starting 
address of your routine. This routine may be located anywhere 
in user memory in either a REM statement or a string. The 
system software keeps track of its location and automatically 
adjusts the variable. 

If you should like to obtain additional reading material on 
other similar applications and sources of supply for kits and 
assembled systems, see the lists at the end of the article. 

System Overview 

The system consists of a buffered motherboard with six 
expansion slots. Two of these slots are designed to accept 
Radio Shack boards. 



Color with a VDP 

Color is produced using the TMS9918A Video Display 
Processor from Texas Instruments, hereafter referred to as 
the VDP. The VDP has the capacity for producing color 
displays and high resolution as well as the ability to create 
and manage 32 additional characters called sprites. A sprite is 
a variable sized character which may be moved smoothly 
over the entire display area in any direction. Each of the 32 
sprites has its screen position determined by its own screen 
address, so creating animated sequences merely becomes a 
series of timed changes to these screen locations. 

The VDP also offers four different Modes, each with 
varying utility depending on the application. Modes I and II 
are graphics modes. Mode I offers up to 15 colors plus 
transparent to be displayed on the screen at once. Up to 256 
unique characters may be defined. In addition to allowing the 
15 colors plus transparent to be displayed at the same time, 
Mode II allows all 16 colors to be present in the same 
character position. Mode I allows any combination of 8 colors 
maximum to be displayed in any one character position. 
Mode II offers up to 768 unique characters per display. 

Because of the unlimited and unrestricted use of color in 
Mode II, this system utilizes it as the high resolution, 16- color 
mode. Mode I, because of its limitation on colors, is used as a 
high resolution, 4-color mode. 

Mode 1 is sufficient for most appliciations, and allows the 
user the advantage of storing up to four pages in memory at a 
time, making paging very simple and quick. Mode II displays 



1. REM*DATA;AS;Xl,x2...Xn: 

A$ is the "name" assigned to a particular set of data. An 
unlimited number of data elements may follow, each separated 
by a semicolon and the last element followed by a colon. 

2. REM*READ A$;X 

Reads an element from the data named AS. 

3. REM*RESTORE A$ 

Resets the pointers to begin at the first data element in A$. 

4. REM*OPEN N 

N is a file name previous! 1 ' defined ugino th^ FIT FN A MF 
command and limited to an alphanumeric of fewer than 3 
characters. 

5. REM*CLOSE N 

Closes the file and "protects" it from accidental access 
during the run of a program. 

6. REM*CIRCLE;X;Y;Radius;Color: 

A subroutine to draw a high resolution circle anywhere on 
the screen with any radius. Any of the 15 available colors may 
be used. 

7. REM*FILL 

Fills the bounded area of the CIRCLE or DRAWTO 
command with the same color as indicated. 

8. REM*FILENAME X$; 

Any three character alphanumeric to "name" a file. As 
such, its location can be stored and recalled by name. It may 
also be a copied page of the display. 

9. REM*VARS A$; 

Allows the user to name a variable being used by the Basic 
operating system to be used also by COLORSIN81 system 
commands such as DATA, FILENAME, FIELD, and 
SOUNDON. This variable may then be manipulated by a 
Sinclair Basic program and instantaneous values used by the 
system. 

10. REM*FIELD:FILENAME: 1 as 2$;2 as 4$;3 as 1$:...X as 
Y$: 

By using the field command, you can assign specific memory 
requirements for each field. In the above example, the first 



Figure 2. The 17 New Commands. _ 



field uses 2 bytes, the second uses 4 bytes, etc. The record 
length is associated to the FILENAME by the system 
software. 

ll.REM*MEMREM 

When used in a GOTO statement, may be used to determine 
the total number of records which may fit in memory in any 
particular file. Uses the information provided by the FIELD 
command to make this calculation. The value returned may 
be POKEd to place additional files in memory. 

1? RFM*SOUNDON:channel.nitch.volume:etc: 
The main method of producing the sounds: the available 
channels are 1-4, the pitch may vary from 0-1023. and the 
volume from 0-15, with the value 15 shutting the tone gen- 
erator off. May be used in conjunction with Basic variables 
which are manipulated by a program. 

13. REM*HRPOS X 

When used with a GOTO statement, then the current X,Y 
coordinates of character X are returned. Allows the pro- 
grammer to determine in software the current location of any 
character on the screen. 

14. REM*MEMLOC 

When run as a GOTO statement, gives an approximation 
of the amount of available user Basic RAM space remaining. 

15. REM*DRAWTO;X,Y;X,Y; X,Y;color: 

Connects any two pixel coordinates on the screen. May be 

extended by as many destination points as desired without 
the final coordinates having to be the same as the first 
coordinate. Any of the available 15 colors may be used. 

16. REM*BIN 

When used in a GOTO statement, calls a special screen 
which may be used to define new characters, sprites, or a 
high resolution screen. 

17. REM*MOVE:FILENAME: origin, destination: 
Allows the programmer to move large amounts of infor- 
mation around in memory, to or from the protected memory 
of the video RAM. Implements the ability to "chain" and 
"merge" programs. 



34 



July/August 1983= SYNC 



NEW FROM TimeUJCRICS 

Computer Control Center. 

For All Timex-Sinclair 1000 and Sinclair ZX81 Computers. 




A handsome, compact, work station that consolidates work 
space and provides remarkably faster, easier operation! 



FEATURES: 

• Effectively eliminates cluttered cables in 
your work area. 

• ON/OFF Switch eliminates plugging and 
unplugging. 

• Accommodates all brands of 16K, 32K, 64K 
RAM packs. 

• Allows provision for Printer and Tape Deck 
hook-up. 

• Holds your Software Tapes in neat, specially 
formed pockets. 

• Made of high impact, black molded plastic. 
The Control Center stands 3%" high, 20" 
deep, 14 1 /2" wide, and accommodates a 13" 
TV screen comfortably angled for maximum 
display. 



• The Computer Control Center costs just 
$29.95. 

COMPLETE MONEY BACK GUARANTEE, 

If, for any reason, you are not completely satisfied, you may 
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occupy 12K of video memory, so only one display may be 
stored in memory at one time. This mode seems best suited to 
games, creating highly detailed images to be dumped to the 
printer, and in creating displays where colors may be used 
either to form bounderies or to show movement. An example 
of this would be in CAD/CAM, where an electronic circuit 
could be displayed on the screen, and the pulses on the 
circuit shown as changing colors on the line. 

Mode III on the COLORSIN81 may best be described as 
the multicolor, block mode. All 16 colors may be displayed 
on a page, but a combination of four colors maximum may 
appear on any one character line. Because of this apparent 
problem, the system software will actively support four colors 
in this mode. Since the block graphics are very similar to 
those of the Sinclair, I have dubbed this the Sinclair mode. 

In Modes I, II, and III, sprites and graphics are supported. 
Each mode has 32 character positions across and 24 lines 
down, the same as the Sinclair. The multicolor mode, Mode 
III, has 64 blocks by 48 blocks on the screen, again the same 
as the Sinclair. However, Mode IV offers 40 characters per 
line with 24 lines down. This mode increases the Sinclair 
screen by 25% and makes word processing and other text 
related tasks far more readable. Formatting becomes much 
easier if you are using an 80-column printer, for you should 
not have the problem of broken words. However, with this 
feature, you lose the use of sprites, and you are limited to two 
colors over the entire screen. However, I am sure that most 
of you will enjoy having a larger screen to work with. 

In the foregoing discussion of the modes of the VDP, I 
mentioned that the system software supported what appeared 
to be less than the potential of the VDP. This is because it 
seemed sensible to make trade-offs if similar results could be 
obtained using one of the other modes. This makes software 
implementation much simpler and allows the use of the new 
commands (in Figure 2) to make programming much simpler. 

However, since all of the functions on this board are 
memory-mapped, your are free to use Basic or machine 
language routines to create anything you wish. Figure 3 
compares the four modes and gives a synopsis of their capa- 
bilities. 

The CULOKMN81 offers a number of special screens which 
may be called as required. These screens will help in defining 
your new character set, defining new sprites, or helping 
construct a high resolution screen in Mode II. These screens 
are interactive in that the user is asked to supply very simple 
information and the computer/software takes care of storing 
that information in the appropriate memory locations. All 
screens and files in this system may be saved on tape, so any 



Figure 3. Comparison of the Modes. 



Characters/line 

Lines/screen 

Number of sprites 

Graphics supported 

Characters supported 

Resolution 

Number colors/screen (maximum) 

Number colors/screen supported 

Maximum number of user defined 

Characters per screen 





Mod* 






1 


2 


3 


4 


32 


32 


32 


40 


24 


24 


24 


24 


32 


32 


32 





yes 


yes 


yes 


yes 


yes 


yes 


yes 


yes 


high 


high 


block 


high 


16 


16 


16 


2 


4 


16 


4 


2 


256 


768 


256 


256 



July/August 1983 c SYNC 



work which you might want to include in another program 
may simply be merged with it. 

The Sound Chip 

Sound is produced with the SN76489A Sound Chip from 
Texas Instruments, This IC offers an 8-octave range and 4 
separately programmable channels, the fourth being a white 
noise generator, Full tone and volume control are accessible. 
Programs may be written in either Basic or machine language. 
Envelope control allows you to produce complex tones that 
simulate the piano or chimes. 

The calculated frequency range in this system is approxi- 
mately 100-10000 Hz, which should be sufficient for most 
applications. The sound is output through an 8 Ohm speaker, 
so the sound quality is very good. 

The application sheets available from Texas Instruments 
create a fairly complex maze of registers and formats which 
must be considered when outputting a specific sound. How- 
ever, the COLORSIN81 software takes care of formatting the 
information when the user loads simple, direct items of 
information into a command line. 

The sound capability has applications in games, in word 
processing programs for positive key feedback , and in security 
systems as an audible noise source. 

The Joystick Interfaces 

Two joystick interfaces are provided on board, but up to 
four may be active at any one time. These interfaces accept 
inexpensve Radio Shack joysticks. The 6-bit resolution is 
sufficient to uniquely identify every character position of the 
screen. If the joystick is used to manipulate the position of a 
sprite, then the sprite may be positioned to the accuracy of a 
half character. 

This feature is designed for applications in alternative input 
mechanisms, in gaming, and in aiding the manipulation of 
screen data. When used with the appropriate software, it 
could be used to change screen information, to move char- 
acters or words from one location to another, or to highlight 
an area on the screen. 

Additional Options 

At the time of this writing, several other options were being 
considered for the board: 1) up to 48K RAM on board, in 
increments of 16K; 2) a solid state interface to allow the user 
to "plug in" programmed PROMs apart from the Sinclair 
memory space and load into memory when needed (up to 
80K of PROMs could be supported on the system, while using 
only 8 memory locations of the Sinclair memory); 3) an 
interface which would emulate a disk drive. The principle is 
the same as the solid state interface, but would use dynamic 
RAMs instead. These new products will become available 
over the next several months. 

Schematic Overview and Circuit Operation 

The motherboard consists of Slot 0, where the Sinclair bus 
originates. The address, data, and selected control lines are 
buffered by ICs 1-4. The PROMs. PI and P2, provide all the 
address decoding required on the board. 

The outputs of the PROM are used to enable ICs 8 and 33, 
which are one-of-eight decoders. Inputs A, B. and C provide 
binary information which is coded by IC 8 to produce one of 
eight active low outputs at one time. On IC 8, input A is 
grounded because address line is used as a mode control for 
the VDP. The eight outputs (select lines) on IC 33 are 
extended to the Radio Shack boards to give the user total 
access for interfacing other homebrew boards. 

IC 9, sections of which have WR inputs and RD inputs in 
addition to the inputs from IC 8, provides the necessary 
signals to the sound and joystick sections on the board. 

July/August 1983 c SYNC 



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The PROMs allow flexibility in design, in that the relative 
addresses of the peripherals on the board could be easily 
changed by changing the programming of the PROM. How- 
ever, to maintain compatibility with other systems, the PROM 
programming should not be changed. 

ICs 10 and 1 1 are latches used to store and continuously 
ouput their contents. In the joystick section, the output of the 
latch is fed into a CD4050 CMOS buffer. This chip is used 
because of its ability to output stable and reproducible voltage 
levels on its output. The output of the chip is fed into a 
resistor bridge, effectively assigning a "weight" to each of the 
data bits. 

The sum of these weighted voltages is then fed to the 
negative side of 1C 22, a voltage comparator. The function of 
the comparator is to output a positive voltage if the positive 
side of the comparator is greater than the negative side, and 
to output a negative voltage when less than the negative side. 
The voltage source for the positive side comes from the 
joystick itself. The joystick has its own 5 volt supply which 
may be varied by the dual potentiometers from to 5.0 volts. 
The effective range, after going through a matching circuit of 
resistors, is approximately 0,25-4.75 volts. Because we are 
feeding 6 bits of data into the section, this 4.5 volts is divided 
by 64 equal units of approximately 0.07 volts. 

Thus, any change in the position of the joystick creating 
greater than a 0.07 volt change could change the position of 
the cursor on the screen. However, in practical terms, we are 
concerned with character positions on the screen, so the full 
precision of the joystick will not be used. However, the 
software compensates for this when using sprites as the cursor 
by developing trend data in direction and speed to produce 
smooth movement instead of the expected jerky movement. 

The function of IC 23, a buffer, is to make visible to the 
Sinclair via the data bus the present condition of the compar- 
ator. The processor, when in the joystick routine, continuously 
outputs data to the joystick latch and then reads the joystick 
port to sense any change in the outputs of the comparator. A 
change indicates that either the X or Y screen coordinate of 
the cursor has been determined. 

in tne sound section, the output ot the latch is led to the 
76489A sound chip as data. The sound chip requires that the 
data be stable for a minimum of 32 clock cycles at 2 MHz. 
Because 2 bytes of data are required to produce a tone, a 
maximum of 3200 different tones may be produced per second 
using machine language programs. 

In Basic, you are not really restricted by the 32 clock cycle 
requirement, for it takes a minimum of 1 ms. to execute a 
Basic instruction. Therefore, a maximum of 500 tones per 
second could be produced. Various frequencies are produced 
by rapidly turning the tone generators on and off with a seed 
tone varied by time. 

The function of ICs 28 and 30 is to divide the 4 MHz 
frequency in half to 2 MHz, the maximum frequency the sound 
chip can handle, The audio output of the sound chip is fed to 
IC 32, an audio amplifier which is used to amplify the tone 
and drive an 8 ohm speaker. The large capacitors are used to 
improve the bass response of the speaker. 

The video section does not use latched data, but receives 
its data directly from the data bus. Since the VDP operates 
asynchronously, data may be read or written to the VDP 
without considering what the VDP may be doing at that 
moment. The VDP has its own internal latches to store data 
until it is able to act upon it. Because of its high clock rate, 
there is no degradation in system throughout. You may run 
machine language programs at full speed reading or writing 
data without the VDP losing any of it. 

The VDP interfaces to the CPU by the data bus, two select 
lines, a Mode Control line which is address on the Z80 bus, 

July/August 1983 c SYNC 



and the reset line from the Z80. On power up, the reset line 
resets all registers in the VDP and clears all memory. It is now 
in a position to be programmed with data. 

Programming is accomplished through the use of the select 
lines, the Mode Control line, and the data bus. The Mode 
Control line differentiates between VDP register accesses 
and video RAM accesses. The CSR and CSW lines, active 
low, determine whether the CPU is reading or writing to the 
VDP. These signals are used to strobe data into the VDP. 
The VDP then performs the required housekeeping duty of 
putting the data in the appropriate register or video memory 
location. 

The VDP also refreshes the dynamic RAMs. The video 
RAM side of the VDP uses multiplexed address/data lines to 
determine a video RAM address. Two bytes of data are 
needed to set the starting address, and one byte of data for 
each data word to be read or stored. 

The VDP features an autoincrementing register, so that, 
once the initial address has been set up, succeeding data 
transfers do not need new addresses. At this point, the VDP is 
processing the data stream as a parallel port. The 10.73 MHz 
crystal may be fine tuned by using the trim capacitor. It is 
used to adjust the crystal frequency to match the pixel rate of 
your TV. The composite video out signal is fed to an RF 
modulator which conditions the signal so that channel 3 or 4 
may be used to display the images on your TV. However, if 
you wish to drive a color or monochrome monitor, a jack can 
be provided. 

Constructing and Debugging the Board 

This system was designed for incremental construction. 
Although the basic price of the system is low, some may 
prefer to spread the cost of the system over a period of time. 
Certain basic sections of the board must be present for others 
to operate, but, once these sections are built, you can extend 
the system at your own pace. 

The system interfaces to the computer in one of two ways: 
1) by a cable running from the expansion port of the cased 
computer to slot of the COLORSIN81 ; or 2) by plugging the 
uncased computer directly into slot on the motherboard. 

If you have an auxilliary keyboard, you can connect it to 
the motherboard using the 25 pin D-type connector on the 
board; however, you can do this only if the computer is 
plugged into slot 0, for that is the only way to connect the 
flex-tail connector of the board to the keyboard input con- 
nectors on the computer. You should decide before ordering 
what approach you would use to interface the computer to 
the system. 

Actual construction time of this board will vary from 3-5 
hours for the experienced kit builder to 10-20 hours for the 
novice kit builder. If you built your own computer, then you 
should have no problems. However, even the novice kit 
builder, taking his time and following the suggestions in this 
article and in the assembly instructions, should be able to 
build this system. 

Before beginning construction, assemble the basic tools: a 
23-40 watt pencil type soldering iron, solderwick, screwdrivers, 
a multimeter, and a set of tweezers. The kit building progresses 
one section at a time, so you should segregate all the com- 
ponements in the kit, arrange them by section, and bag each 
section. This will ensure that all the parts you need are 
present and will eliminate much searching when you actually 
are building the kit. 

In general, the basic sequence of inserting parts onto the 
board should be: IC sockets, capacitors, resistors, diodes, 
followed by other discretes such as potentiometers, variable 
capacitors, and transistors. This approach allows you to use 
your best judgment in the placement of the components. 

July/August 1983 c SYNC 



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39 



The Power Supply 

I recommend a 15 volt, 5 amp power supply to accom- 
modate future expansion of this system. When fully built with 
the computer and a 64K RAM pack attached, the power 
consumption approches 2.0 amps at 5 volts. If you intend to 
add more than 2-3 boards to the system, you might need to 
add a second 5 volt regulator. Although only +5 and +9 volts 
are required in this design, the board has room to accom- 
modate + 12 volts and -5 volts, obtained using an inexpensive 
voltage converter. 

By purchasing the proper type of power supply, you will 
eliminate much frustration in the future. The power supply 
should have a regulated output. (When ordering a kit or 
assembled system, inquire about the availability of a power 
supply if you need it.) 

The Power Regulating Section 

The first part of the board to be built is the power regulating 
section. This is made up of 3 regulators and heatsinks, 1 IC, 
and several resistors, capacitors, and diodes. If you put the 
components into groups, assembly will proceed much faster. 
Starting with one of the voltage regulators and its associated 
parts, assemble the parts to the board and solder using the 
component placement layout in Figure 4. 

Figure 5 is a schematic of the system and should be used 
when debugging the board. You might want to test the power 
supply before connecting it to the board. Turn power on to 
the supply with no connections to the motherboard. You 
should have a voltage of 15-18 volts. After all the components 
for the power section have been soldered, attach the power 
supply and turn on the power. Referring to Figure 4, locate 
appropriate test points and adjust the appropriate variable 



potentiometer until the desired voltage is obtained. When 
inserting components into the board, pay particular attention 
to polarity of the capacitors and diodes. Improper placement 
will result in poor performance. Once voltages are set to the 
indicated levels, proceed to building the motherboard and 
buffers. 

The Motherboard 

Assemble all the parts for the motherboard and buffer 
section. Insert the IC sockets, followed by the connectors 
and other components. Carefully inspect your work for solder 
bridging, especially on the connectors. For thoroughness, 
you might want to check for continuity from one connector 
to the next; remember that the address, data, and certain 
control lines go through the buffers. 

At this point, you have a fully functional motherboard and 
may begin using the power of the Sinclair to help in making 
the rest of the system operational. 

To prove that your computer may help, attach it to the 
system, insert some known working board, other than a 
memory board, into one of the other slots and turn on the 
computer. If the board operates normally, then all aspects of 
the motherboard are operating as expected. If the computer 
works but the peripheral board does not, then the problem 
lies in the soldering of the connectors or IC sockets. If the 
computer does not produce a display, then the buffers are not 
operating correctly, and again soldering should be checked. 



The Address Decode Section 

This section is made up of 5 ICs and sockets, assorted 
capacitors and resistors. Insert the parts indicated, power the 
system up, and check for proper voltages by referring to 

Figure 4, Component Layout of COLORSIN81 Board.— 



^X + A. ^ ° 



DC 



1 



^0" 



9 



I 5PKR uui 






' — i 


2 A 


cc 

2B 




22 









•— f Video 
•— I *»"' 



I I I I I I I 
— X — ^cxpcs 

I II I IN 



u 




11 




24 




CC 

IA 



Resei \. 

on -board RAM 



Reserved 
for future 
expansion 









c= 




1 — } 














Auto 


m.M 


V 






CZ3 


Jump 
Circuitry 

o o 












RF 



r? 



:i 



1 Vr3 I 

I I 






40 



July/August 1983 c SYNC 



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Figure 6. If you have access to an oscilloscope, you can test 
this section by POKEing the select addresses as indicated on 
the schematic. If not, then you will have to wait until the next 
section is added to prove that the address decode section is 
operational. 

The Joystick Interface 

This section is made up of 4 ICs and sockets, capacitors, 
component carriers for the resistors and a large assortment of 
resistors. Begin by assembling the component carriers as in 
Figure 7. Now that 90% of the parts are assembled, you can 
concentrate on the sockets and remaining components. Insert 
the ICs, power the system up, and check voltages to the ICs. 

Once done, enter Listing 1 and RUN it. Check the output 
pins on IC1, You should see a rhythmic change in the 
measured voltage. If you do not see this activity, then check 
your soldering on both the address decode and joystick 
sections. If you still are unable to detect the indicated response 



to the program, then make a thorough check with a continuity 
tester. Check each line in the two sections to verify that no 
shorts exist. 

Finally, if no problems are detected, then try one of two 
other approaches: 1) contact a friend who has a logic probe 
or an oscilloscope and ask for assistance in finding the 
problem; or 2) purchase additional parts from a supplier such 
as Radio Shack to isolate the problem. Although no one ever 
likes to admit it, occasionally component failure is the cause 
when a project does not work. 

After you are able to observe the desired response to the 
program, insert ICs 22-24 and the component carriers as in 
Figure 4. Power the system and enter Listing 2. If you have 
purchased a Radio Shack joystick, assemble it as in Figure 8. 
Connect the joystick and RUN the program. 

You should be able to place the cursor in each of the four 
corners of the display. Do not be alarmed at the response of 
the joystick. The machine language program will run many 



Figure 5. Schematic for COLORSIN81. 



MREQ 

RESFT 

RD 

WR 



2 






I ,i4 
I 



to Sinclair Bus 



74LS367 



f 5V 



u3 



ul5 



A15 
A14 
AJ3 
A12 



^ 



74LS245 



MSB 
u5 




is D2716 
74LS04 



3Z> 



74LS245 



6301-15 



i£J fftr* 



74LS245 



LSB 
u6 




74LS257 

2 



uie "~\ 



-± I I 15 

I I 
I I 



"B^ril 



:sr 



DATA bus 



'TS 



^ 



O 55 u3 3 



l°Tl 



74LS138 



% 



_±E!> 



74LS02 



rO|T7 



USER 

DEFINED 

5(8] 

14346 



14348 



74LS138 



[X, 



K>c4 



7 6 5 4 3 2 10 

DATA 
CSR 

csw 



MODE 
RESET 



Ul2 

TMS 
991 8A 



RAS 



7E 



Hd|- 

10 7 MHi 



42 



July/August 1983 E SYNC 



limes faster than this Basic program, As the cursor position is 
changed from corner to corner, you might take a voltage 
reading at pins 1 and 2 of the voltage comparator, IC 22. You 
will see the maximum voltages that may be outputted to the 
two sides of the comparator. 

Sound Section 

Assemble the parts for this section and solder. You should 
have 4 IC s and sockets, a crystal, resistors, a variable resistor, 
2 large capacitors, and a number of small capacitors. Do not 
insert IC 32 yet, as you do not want to output a load without a 
speaker attached. However, if you want to connect the 
speaker at this time, you can leave it in. 

Enter Listing 1 again, changing line 40 to POKE 14344. Run 
the program to again observe the rhythmic changing of the 
voltage levels, particularly on pin 2 of IC 10. Do not be 
concerned with the hiss that you might hear from the speaker. 
The sound chip occasionally outputs a sound on power up. 



You can reduce the volume by adjusting the variable resistor. 
Enter the program in Listing 3 and RUN it. You should 
hear a series of tones which sound like a chime. Adjust the 
variable resistor until succeeding runs of the program produce 
the tone at the desired volume level. Now proceed to the next 
section. 




~^k 



13 




13 








13 


1 


13 




! 1 


6 




in 




10 


10 






10 




10 


10 


l :, 




! I 


1 1 




ii 




5 




i ) 


12 


"? 


1? 




i? 


12 


1.' 


l? 


6 


6 


6 




A 


6 




6 


■ 






/ 




7 ~ 


7 




• i 




j 
















d 


4 


d 






4 


A 


j 








!S 


IS 




i '■ 








3 


3 







100 O" 




It 



Figure 6. Power Connections 

P/N GRD 5 



+ 9 



1,2,3 

4,23 

5,6 

7 

8,33 

9 

10,11 

12 

14 

15 

16,30 

17 

18,19 

22 

24 

28 

31 

32 

34,41 



74LS245 

74LS367 

6300-1 J 

74LS08 

74LSI38 

74LS02 

74LS373 

TMS9918A 

74LS08 

D2716 

74LS74 

74LS00 

74LS257 

LM339 

CD4050 

74LS04 

76489A 

LM386 

4116-150 



10 
8 
8 
7 
8 
7 

10 

12 

14 

12 
7 
7 
8 

12 
8 
7 
8 
4 
16 



20 

16 

16 

14 

16 

14 

20 

33 
7 

24 
14 
14 
16 

I 
14 
16 

6 
9 



+ 12 
8 



Figure 7. 



261 K 
147 K 

75 K 
38 K 
19 K 
10 K 
100 K 
CC1A 



100 K 

51 K 
5 K 
13 K 
5 K 

2.6 K 
1 K 

CC1B 



10 K 

10 MEG 

1 K 

10 K 

10 MEG 

1 K 

20 pf 

CC2A,B 



Insert the resistors and capacitors into the component carriers as shown. Resistors 
in CC1A. B are \% resistors. CC2A, B have 5% resistors. 



Figure 8. Joystick. 



+ 5V 




Ground 



Vssemble the Radio Shack joystick as shown. You should get .i dual 100K 
joystick. 



July/August 1983 e SYNC 



43 



20 LET 2=14350 



_ Listing I. Latch test,. 



»R 1 = 1 It) 128 
40 PCM E 

XT I 



Listing 2. Cursor test. 



Video and Video RAM 

This is undoubtedly the section many of you have been 
waiting to get to. 

This section consists of 3 ICs and sockets, an RF Modulator 
and/or a monitor jack, a variable capacitor, a crystal, and 
several resistors and capacitors. Insert and solder all the 
components as in Figure 4. 

Enter the program in Listing 4 and RUN. This program 
loads data into memory locations in video RAM and then 
reads these same locations and prints the results. You will 
notice that the program increments the data in multiples of 2; 
if, when printing the information to the screen, you notice a 
zero appearing where a number should be, this can aid you in 
determining that you might have a bad solder point in the 
section. It will even help to identify which line might be bad 
in that each bit of data has its own pin on the RAM chips that 
it enters and exits. If the demonstration program does not 
operate as expected, again check soldering quality and con- 
tinuity. When the section works, you are ready to add the 
PROM interface and the automatic jump circuitry. 

This section will be revised later to make use of the new 4416 
memory chips from Texas Instruments when they become 
available. The required chips will be reduced from eight to 
two. This offers many advantages to the kit builder and user 
because debugging is much simpler and system reliability is 
increased. These chips could also be used whenever the on- 
board memory option is added and whenever possible in other 
suitable applications. 



.Figure 9. Switch Settings. 





12 3 4 5 6 7 8 


A 


1 10 




12 3 4 5 6 7 8 


B 


00000000 



1 =On 

1 = Off 



5>et the switch as in A to cause an automatic jump to the system PROM 
Use the settings in B when running unmodified Sinclair programs. 

PROM Interface and Automatic Jump Circuitry 
The PROM interface consists of 1 IC and socket. Insert 
and solder and check for proper voltage levels. The Automatic 
Jump circuitry consists of 4 ICs and sockets, an 8-position 
switch, 2 transistors, and 2 resistors. Insert the components, 
solder and check for proper voltage levels. 

You might notice that you no longer have a cursor on the 
display. This is expected and normal. If the PROM was 
™ ed ' the computer is now executing instructions in this 
PROM and is waiting for you to input something through the 
keyboard. to 

At this point, you might want to disconnect the TV cable 
from the Sinclair and attach it to the RF modulator on the 
motherboard. Set the switch positions as in Figure 9 and 
power the system up. The prompt "READY" should appear 
on the screen. At this point you have a fully operational 
system ready for you to develop applications. 

If you have a video monitor, or another TV, you may want 
to connect one to the computer and one to the motherboard 
In this way you can see what is happening to the Sinclair 
display. 

When running application programs which have not been 
converted to run on this system, set the switch positions as in 
Figure 8, power the system up, and observe the results of the 

44 






■ 



60 

I 10 



LET > 

LET i 
SLOW 

IF PI 

I 
: - 1 TQ 64 

1HFN GOTO 170 

PF ItlT AT 

I i 
STOP 

GOTO 180 



I 



1 

20 



Listing 3. Chime demonstration. 

LET 

REM TURN OUTPUTS OFF 
; Or E 2 , 159 
40 POKE Z , 193 

POKE Z, 2:55 
65 PPM INPUT AMv rHING 
' A* 

iBLE THE OUTPUTS 
POKE 7, 140 
90 PQ 
100 POKE Z, 170 
npE Z, 5 
REM NUMBER OF BELLS 
OR B-0 TO 1 1 
140 FOR 1=145 TO 159 

1 60 POKE Z , < ] i 
170 REM DELAY 
t80 FOR D»0 TO 1 

190 NEXT D 
NEXT I 

GOTO 10 



Listing 4. VDP and memory verification. 



LET . 

PAST 

LET WR- 14349 

LET R|i 

LET RRD=14 

REM SET UP STARTING ADDRESS 

POKE WR, 

POKE WR, 

REM ENTER DATA 

LET Z-Z+l 

Pop I = j. TO 50 

LET Z * 

POKE 

NEXT [ 

OAT A 
POKE WR.O 



40 
50 
60 
70 
80 

[ •• I 
140 

175 
180 

1 90 



POKE WR,0 
2*1 ' 

SLOW 

FOR 1=1 TO 

LET Z = Z*2 

PR I ! I 

PRINT CHR*0; 

NEXI 

PR IN! "DONE" 






Try varying the numbers in lines 140 and 180. Observe the effects. 



July /August 1983 e SYNC 




game 



COMMODORE/ SINCLAIR 
VIC 20 / ZX 81 

(16 K RAM) 

imly $14,95 



Plea.se rush me 
check or money order * 14.95 
Payable to B MS 



C*m»*Ot** Wa > 



SVZ5 



S;*U*f* Zktt 



Quantity 



. STATE 



add , 

sales I 
lax 

SHIPPING 1J50 

TOTAL 



-to B.M.S. Pa BOXJIO/^ ^E^RBORN^MJ^^.2^ _ | 



program through the Sinclair TV display port. If the sound or 
joystick features are to be used, then at some point early in 
the program LET Z = USR x, where x represents the 
beginning of the PROM subroutines for these features. 

Programming the System 

The joysticks are enabled in this system by POKEing six 
memory locations. The first location tells the software how 
many joysticks are to be active during this time period, and 
the second location actually enables the joysticks. Up to four 
joysticks are supported by the software. The next four loca- 
tions are used to store the code number of the character to be 
used as the cursor for each joystick. If you wish to use sprites 
to indicate the position of the cursor, then zeros should be 
POKEd into these locations. The software will automatically 
use the four highest priority sprites as cursors. 

The sound features are implemented by the SOUNDON 
command. The three parameters in the command are used to 
choose the desired tone generator, the pitch to determine the 
frequency, and the volume which is used not only to vary the 
volume, but also to turn a tone generator off. You can use 
variables for any of these parameters so long as they have 
been declared previously by the command VARS. You may 
also add multiples of these three parameters in the same 
REM line if you wish, the only condition being that separate 
groups be separated by semicolons and that a colon follow 
the last parameter in the REM line. 

Most of the other commands are self-explanatory, and a bit 
of experimenting will quickly enable the programmer to 
produce application programs far easier than ever before and 
in much less time. 

For those who purchase a kit or an assembled system, the 
accompanying manuals will detail in far greater depth how to 



program the system and develop applications. Sample pro- 
grams and applications will be included to help encourage 
the new owner to discover the true power of this svstem as 
compared to the unmodified Sinclair. 

Conclusion 

I am sure that many of you are looking forward to using 
your new Sinclair. You should! You now have one of the 
most powerful computers on the market for under $1000. 
You have the superior graphic capability of the Texas Instru- 
ments 99/A computer, the high resolution of the Apple the 
easy editing of the TRS-80, and sound comparable to the best 
on the market. You have the advantages of easy expandibility 
and interfacing, of adding new utilities on PROM to further 
expand the capabilities of the system, of adding new RAM to 
the system inexpensively, and of connecting your keyboard, 
if you have one, to the system. Best of all, you have the 
advantage of being able to expand your system at will from 
the large selection of inexpensive Sinclair peripheral equip- 
ment on the market. 

I am sure that many of you are indecisive about investing in 
this type of expansion because a "better" computer might 
become available, or because this is your first computer and 
later you might decide to get another. Well, this system is port- 
able. It may technically connect directly to any Z80 based 
computer such as the TRS-80. You might not be able to use 
the PROM designed to work with the Sinclair, but adding 
several routines to accommodate the TRS-80 should not 
be at all that difficult. Also, since most of the Z80 signals 
are duplicated in some manner on other microcomputers on 
the market, interfacing should be relatively simple. So not 
only are you investing in your Sinclair for today, but also you 
are looking forward to extending the capabilities of your 
future system. 



LIMITLESS EXPANSION FOR SINCLAIR/TIMEX 



FLOPPY DISC INTERFACE $179*/-4 drives, any size* single/double 

DENSITY * INDUSTRY STANDARD IBM FORMAT -ON BOARD DOS IN ROM 
RIBBON CABLE CONNECTIONS FOR MAXIMUM RELIABILITY w * 

WOO TIMES FASTER THAN CASSETTE + 

5.25" DOUBLE DENSITY FLOPPY DISC DRIVES $189 ea * * 
POWER AND CABLES FOR 2 DRIVES $79 

STD BUS INTERFACE $99 complete with ribbon cable 

CHOOSE FROM 300 PERIPHERAL INTERFACES, 60 MANUFACTURERS 

CENTRONICS PRINTER INTERFACE $119 complete with * 

PRINTER CABLE, SOFTWARE IN ROM 

DIRECT VIDEO MODIFICATION $25 we install $15 you install 

WORD PROCESSING SOFTWARE PACKAGE $15 machine language 

BOX 18093 AUSTIN 

llllllllllllll V5u5 TX 787 60-8093 

W *+* (512) 385-7405 




46 



July/August 1983 c SYNC 



CONVERT YOUR ZX. 

FULLER MICRO SYSTEMS ADD STYLE, POWER, VERSATILITY 
AND FULL TYPEWRITER KEYBOARD OPERATIONJTQJTHE 
AMAZING ZX81 COMPUTER! — ' ^lp\ 



THE FULLER FD42 SYSTEM 

The ideal Christmas Gift for 
ZX81 users. 

If you already are the proud owner of the fastest selling small computer in 

the US or maybe have a friend or member of the family who's a ZX 

fanatic what better buy is there this Christmas than the famous Fuller FD42 

System! It converts your Z <81 into a sturdy, attractive and professional unit, 

with full sized typewriter keyboard. All the Sinclair 

ZX81 keys are duplicated with extra shift and 

new line keys. The professional momentary 

action key switches have a guaranteed life 

of 10 operations, and the whole unit 

comes to you complete with a money 

back guarantee. 

IT'S EVEN CHEAPER IN ij j «m m ^**n* 

?ra2!Eoa* and case M. JPSE flfTUm/OUr ZX81 

$67 95 + $6p&f>. 

FD 42 keyboard kit 



$37 



95 



+ S4 p& p. 






from this to this 



ITS SO EASY 
TO INSTALL! 

You simply unscrew the ZX 
printed circuit board from 
its base, screw it into the 
the new FD case, and 
plug in the keyboard. No 
soldering or technical 
knowledge required. 

ZX81 MOTHERBOARD 

Also easy to install! The FD system Motherboard fits 
inside the Fuller case and allows expansion to the ZX 
memory and 1 /0 facilities 



FULLER MEMORY EXPANSION 

a massive boost for your ZX81 ! 

The basic ZX81 has only 1 k of RAM - now you can 
add on an enormous 1 6 or 64k with our FD Memory 
Modules. Cfr^Q-95 

FD16K *T S n*p. 

_$59 95 

+ S4 p&p. 

$129 95 

+ S4 p& p 
■ Please supply the following items: 



FDl6k to fit inside Fuller case 
FD64k Memory Module 



2 slot $30*° +S4 p& p. 



.3 slot 



95 

$39 95 



+ $4 p& p. 



195 



NEW! - Programmable Sound 

Generator - adds exciting new 
sounds to the ZX81 range 

Separate P.S.U. 9 volts @ 2 amps 

Plug Planner -complete with 3 metres cOiC^ 

of cable and power jack ^JO^+sepap 

Ram Adaptor Board - adapts Sinclair RAM ^ . Q g5 

pack to fit inside Fuller case $7ir +S4p&p 



$39-^ + $4 p&p. 

+ S4 p&p. 
95 



$14 95 



MICRO 
SYSTEMS 




Mail to: FULL MICRO SYSTEMS, 

The ZX Centre, Sweeting Street, Liverpool 2. 
England U.K. Telephone: 051-236 6109 



ITEM 


PRICEt 


Qty 


TOTAL 


Fuller FD System 42 Keyboard & case 








Fuller FD System 42 (Kit form) 








Fuller FD System Motherboard 








Fuller FD 16K. Memory Module 








Fuller 64K Memory Module 








Sound Generator 








FD PSU 9 Volts at 2 amp. 








Fuller FD Shipping and Handling 








[ AD CODE 











Mail to FULLER MICRO SYSTEMS, 

The ZX Centre, Sweeting Street, Liverpool 2 
England U.K. 

Name 

Address 

City /State/Zip O*] 

t US Dollars SY.7.83 




References 

I wish to acknowledge my indebtedness to the following 
authors and publishers for their kind permission to use 
concepts from their work in developing this project: 

"Add Programmable Sound Effects to Your Computer," by 
Steve Ciarcia, Byte, July 1982, McGraw-Hill Publishers. 

'Build a Joystick A-to-D Converter for Your TRS-80 Model 
I/III," by William Barden, Byte, January 1982, McGraw-Hill 
Publishers. Used by courtesy of Howard W. Sams & Co., Inc. 

"High Resolution Sprite-Oriented Color Graphics;' by Steve 
Ciarcia, Byte. August 1982, McGraw-Hill Publications. 

"A Guide to Using the Texas Instruments SN76489A Sound 
Generator," by Ted Mahler, Texas Instruments Application 
Report. Courtesy of Texas Instruments Incorporated. 

"Advanced Circuits, SN 76489A," November 1981. Courtesy 
of Texas Instruments Incorporated. 

'TMS9918A/9928/9929 Video Display Processor:' 1981. 
Courtesy of Texas Instruments Incorporated. 

For reprints of the articles appearing in Byte Magazine, 
write to: Byte Publications, 90 Main St., Peterborough, NH. 

For further information or technical literature from Texas 
Instruments, write to: Texas Instruments Incorporated, Cus- 
tomer Response Center (1-214-995-6611). When requesting 
information, be as specific as possible and mention this article 
for best results. 

Suppliers and Technical Information 

The parts for this project may be ordered from: 

Daniel G. Roy, 99 Andover St., Lawrence, MA 01843. 1- 
617-682-5132; 6:00-7:00 p.m. 

CAI Instruments, PO Box 2032, Midland, MI 48640. 1-517- 
687-7343; orders: 9 a.m. to 4 p.m.; technical information 6-7 
p.m. 

Following is the parts list. Enquire concerning assembled 
price, power supply, and any options desired. 

Complete kit of parts (PC board, documentation, PROM, 
and all necessary parts, less power supply): $159.95. 

PC board, PROM, documentation: $59.95. 

Connector, address decode, and buffers: $29 95 

Video: $49.95. 

Joystick interfaces* ^Q 9^ 

Sound: $14.95. 

Automatic jump circuitry: $4.95. 



Motherboard, line buffer, and address decode circuitry 



Power 


Parts I ist 

Regulating Circuits 


U29 


LM350 1 


U25 


LM317 1 


U26 


7812 1 


U27 


ICL7660 1 




0.1 u,f capacitor 2 




10.0 ixf capacitor 4 




1.0 jitf capacitor 2 




tant 




1N4004 3 




240 Ohm resistor 2 




5% 




TO-220 heat 3 




sinks 




socket, 8 pin 1 




5K variable 2 




resistor 



+ 5 volts, 3 amps. 
4-9 volts, 1 amp. 
+ 12 volts, 1 amp. 
— 5 volts, .1 amp. 



diode 



U 1,2,3 74LS245 
U4 74LS367 
U5,6 6300-IJ 
U7 74LS08 
U8,33 74LS138 
U9 74LS02 
U28 74LS04 
R1-R8 
P0-P4 
P5-P6 


3 
1 
2 
1 

2 
1 
1 
8 
5 
2 




11 


Sound Circuitry 




U10 74LS373 
U31 76489A 
U30 74LS74 
U32 LM 386 

4,000 MHz 


1 
1 
1 
1 
1 
1 
1 
1 




1 
1 
1 
2 
1 
4 


Joystick Circuitry 




Ull 74LS373 

U24 CD4050 

CC1A,B 

CC2A,B 

U22 LM339 

U23 74LS367 


1 
1 
2 
2 
1 
1 




8 
2 




4 


Video Circuitry 




U12 TMS9918A 
U34-41 4116-150 


1 
8 


10.7386 MHz 


1 


VC1 


2 
1 
1 


Urn 1082 


1 
1 




1 
9 


Prom and Automatic Jump Circuitry 


U15 D2716 
U16 74LS74 
U17 74LS00 
U18,19 74LS257 
SW 1 


1 
1 
1 

2 
1 




6 



line buffers, bidirectional 

line buffer 

256x4 programmed proms 

2 input AND gate 

3-to-8 decoder 

2 input NOR gate 

hex inverter 

IK, 5% resistors 

Sinclair 46 pin connectors 

Radio Shack 44 pin connectors 

assorted 14,16,20 pin sockets 



8 bit latch with output enable 

TI sound chip 

dual D-type flip flop 

0.4 watt audio amplifier 

crystal 

1.0K, 5% resistor 

2.2K, 5% resistor 

10.0K, 5% resistor 

2.7K, 5% resistor 

10.0K, variable resistor 

0.1 u,f capacitor 

250 jitf capacitor, 25 volts 

10.0 /xf capacitor, electrolytic 

assorted 8,14,16 pin sockets 



8 bit latch with output enable 

CMOS buffer 

component carriers (see Figure 7) 

component carriers (see Figure 7) 

dual comparator 

buffer 

assorted 8,14,16 pin sockets 

dual 100K Ohm Radio Shack 

joysticks 
component carriers, 16 pin 



TI VDP 

4116 RAM chips, 16Kxl, 

150ns. 
VDP crystal 

33 pf capacitors 

9-35 variable capacitor 

IK variable resistor 

100 Ohm 5% resistor 

RF modulator 

video monitor jack (optional) 

assorted 16,40 pin sockets 



2K X 8 bit prom, 5 volts only 
dual D-type flip flop 
2 input NAND gate 
2 to 1 multiplexors 
8 position dip switch 
assorted 14,16,24 pin sockets 



♦also required, 49 pc. 0.01 uf decoupling capacitors 



i 



48 



July/August 1983 z SYNC 




FOR 

SINCLAIR 

AND 

TIMEX 

SINCLAIR 

OWNERS 

ONLY 



If you own a Timex Sinclair, a ZX81, 
or any other Sinclair computer, 
you've probably discovered that 
the big microcomputer magazines 
cover only the bigger computers. 
Where can you find helpful articles on 
the Sinclair? In Sync! 

Sync is the one magazine that's 
written exclusively about Clive Sin- 
clair's marvelous inventions, the Sin- 
clair computers. And it's the one 
magazine to read if you want to get 
more from your Sinclair. 

You'll find program listings for 
games, helpful programming tech- 
niques, hardware upgrades, math and 
science programs, news of new prod- 
ucts for the Sinclair— in short, every- 
thing you need to use and enjoy your 
Sinclair to the fuiiest. 

In just two recent issues, for exam- 
ple, we covered: 

□ Putting a Reverse Character in a 
String 

D How to Double Your Memory 

□ Least Squares Data Analysis With 
theZX80/81 

□ Space Warp: A Graphics Space 
Game 

□ How to Reduce "Blank Screen 
Time" 



□ Storing Three-Letter Words in an 
Array 

□ Software Review: ZX Galaxians 

□ An Introduction to Expression Eval- 
uation 

D Short Programs Just for Fun 

□ The ZX81 Parser and User-Defined 
Commands 

□ Understanding Floating Point Arith- 
metic 

□ Handling Strings from Another Di- 
mension 

□ Book Review: Understanding Your 
ZX81 ROM 

□ How to Add a Keyboard to Your Sin- 
clair 

□ Translating Other Basics: DEF on 
theZX81 

□ Six Outer Space Games— With Pro- 
gram Listings 

□ Hardware Review: Sinclair ZX Spec- 
trum High Resolution Color/Sound 
Computer 

If you own a Sinclair microcom- 
puter, Sync is the only computer mag- 
azine you really need. Subscribe now 
to Sync, and you can save up to 33%! 
Just complete and return the post- 
age-paid reply card or the coupon 
at right. 



SAVE UP TO 33% 
ON SYNC! 



si_|ncz 

CN 1986- Morristown, NJ 07960 

Please send me 
Sync for: 
D One year (6 issues) for $12.97— 

I save 19%. 
D Two years (12 issues) for $22.97— 

I save 28%. 
D Three years (18 issues) for 
$31.97-1 save 33%. 

Savings based on full 1 -year subscription price 
of $16. 

Mr. 
Mrs. 
Ms._ 



(please print full name) 



Address. 



^Apt.. 



City_ 



-Zip- 



State 

CHECK ONE: 

□ Payment enclosed. □ Bill me later. 

Offer valid in U.S. and possessions only. Please allow 
60 to 90 days for delivery of first issue. 

NEW SUBSCRIBERS ONLY 



Connect a Monitor to the TS1 000 cass r. Lewart 



Using a Timex/Sinciair 1000 with a 
video monitor instead of a TV set gives a 
dramatic improvement in the picture 
quality. This is particularly so with respect 
to the TS 1000 graphic symbols. 

Although the computer comes only 
with a standard RF output, it is com- 
paratively easy to provide an additional 
monitor output. My modification requires 
only a single transistor: a Radio Shack 
276-2009 or equivalent. No traces have to 
be cut on the TS1000 board. The result is 
a display with full brightness and contrast 
on any run-of-the-mill monitor. The mod- 
ification should take no more than 10 
minutes to perform. 

To perform the operation, first remove 
the Phillips screws on the bottom of the 
computer (some of these screws are hid- 



Cass R. Lewart. 12 Georjean Dr., Holmdel. NJ 
07733. 



_FlRure 1. 

TS1000 bottom view 
(not to scale) 



Expansion edge 
connector 



RF modulator 



Mini 




RF Plug 
'to TV 



Shielded cable 
to monitor 



J ( To tape 
recorder 



IT'S SO EASY 

To expand your computer when you have 

the Solutions 

Solutions is proud to announce the arrival of THE EXPERIMENTER'S 
SOLUTIONS BOOK. It will show you how simple it is to add sophisti- 
cation to your Timex Sinclair 1 000. Here are some examples: 

• A Buffered Expansion board that allows for a great number of quick and 
strong connections. 

• Different types of Parallel I/O. 

• The use of Parallel I/O to control AC and DC circuits. 

• RS232 Serial Communications. 

• Parallel Printer Interface. 

• Real Time Clock 

And more! 

Written in a clear, easy to follow style everything is included; wiring 
diagrams, software listings, parts lists, theory of operation, etc. There is 
also an introduction to help you understand the Timex Sinclair Expan- 
sion port. 

THE EXPERIMENTER'S SOLUTIONS BOOK $9.99 

Don't forget Solutions also carries an ever expanding line of business 
and educational Software. 

SOLUTIONS 
P.O. Box 1144 

Piscataway, N.J. 08854 



50 



den under the rubber feet). Then make 
the soldered connections as shown in 
Figure 1. Tap the video input to the RF 
modulator and use one of the other two 
inputs as power supply (B+) for the tran- 
sistor. To get B+ on the lead indicated, 
the nomputer channel switch must be kepi 
in the Channel 2 position. 

The video voltage at the input to the 
RF modulator is approximately 1 Volt 
peak to peak. This would be sufficient to 
drive a monitor with sufficient contrast 
and brightness. However, the source 
impedance at this point is nearly 1000 
Ohms. Therefore, a direct connection to 
a 50-75 Ohm monitor means a voltage 
drop to less than 100 mV. The result 
would be marginal brightness and con- 
trast. The NPN transistor connected in 
the emitter follower configuration, as 
shown, provides the required impedance 
transformation, so that the full 1 Volt 
peak to peak reaches the monitor inde- 
pendent of the impedance of the 
monitor. 

Next, decide where to mount the video 
monitor output jack. You can mount it 
next to the RF output, or, if you are not 
planning to use the RF output, you can 
use the RF jack and bypass the RF modu- 
lator. My own solution, though not a very 
neat one, was to let two wires dangle 
through one of the holes and to connect 
the wires to the monitor with clip leads. 

B 

July/August 1983 c SYNC 



LTEXT AND ZTEXT + 

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takes the text and sends it to the screen or ZX printer justifying it and formatting according to commands 
embedded in the text Included in the range of commands are such useful operations, as string search, 
string replacement and a merge facility enabling a skeleton document to be filled with variable 
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Adding A Joystick 

TO The TimeX-Sinclair 1 000 James W. Stephens 



Most active graphics programs for the 
TS1000/ZX81 use the unshifted cursor 
keys to control movement. Even though 
you can struggle your way through the 
program, this type of control is much like 
trying to drive an automobile using only a 
keyboard. It is just not natural. 

After running my flight simulation pro- 
gram for a few days, I decided that I 
could probably improve my sloppy land- 
ings if I had a control stick. 

Figure 1. Printed circuit board 



Figure 2. Cable connector to ZX81. 




JUMPER THIS CENTER 

LAND TO KB4 - SOLDER - 



The Atari Controller 

My son's Atari controller's plug fitted 
perfectly into the 15-pin RS232 connector 
that I used for my full-sized keyboard. 
Since the Atari stick is just a four-position 
switch, it seemed that a little rewiring to 
the connector would be all that was 
required. 

However, when I checked the Atari 
plug with an ohmeter, I discovered that 
several of the contacts were wired with a 
common line. The controller would have 



James W. Stephens. 2324 DennywocxJ Dr.. Nash- 
ville. TN 37214. 



52 




& ft I I I | | I I | ^) \ 




FRONT VIEW 

MINIATURE CONNECTOR 
MALE-AMPHENOL SIZE 25 
OR SIMILAR 



KB0 KB2 



to be rewired. As a result, it could no 
longer be used with the Atari VCS. So I 
went to our local Atari distributor and 
found that he had joysticks in stock for 
only $8.50. 



.Figure 3> End view of Atari plug. 

KB1 D; 



to o 6 o A 
lo o o o o \ 



KB3 KB4 Dl KB2 



The controls of the stick are simple 
indent type buttons on a printed circuit 
board. The diagram in Figure 1 shows 
how these are mounted on the board. 
The movement of the stick pushes plastic 
fingers down to close either one or two of 
these contacts at a time. When I com- 
pared the circuit to those of the ZX81 
cursor controls, I found that only one of 
the copper foils had to be cut and jump- 
ered. This rewiring is as shown in Figure 
1. 



Converting the Atari Controller 

All that is required to convert the con- 
troller is to cut gently the copper foil on 
the circuit board as shown in Figure 1 
and jumper this switch connection over 
to the edge marked KB4. However, the 
proper connections must be made at the 
15-pin connector as shown in Figure 2. 
The connector is then hard-wired into 
the ZX81 printed circuit board as shown 
in Figure 4 . The male connector is wired 
directly to the original keyboard socket 

— Figure 4. Printed circuit side of ZX8t board. _ 




ODD ' 

8 7 6 5 4 3 2:' 



connections by a short length of ribbon 
cable. This connector can be mounted 
into the top right-hand side of the case 
for good access. 

Use great care when soldering to the 
socket pins since you will be very near 
small diodes which are sensitive to heat. 
Pre-tin your ribbon cable leads and solder 
bridges. Even though you do not need all 
the connections for the joystick, it is a 
good idea to wire all of the connections 
now since you may want to add a full-size 
keyboard later. 

Guard against possible static discharge 
when handling the bare circuit board of 

July/August 1983 c SYNC 



TIMEX 



Sinclair- in an 



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- 6 7 / 8 " x 6%" x 1%" - 12 oz. • Expandable - Optional 16K 
RAM module •Single-key entry commands 

• Educational • Unique syntax-check report codes for 
error identity • Accurate to 9 1 A decimal places for full 
range math and scientific functions • Graph drawing 
and animated display • Advanced 4-chip design 
combining power, portability and affordable price. 
TS1000 INCLUDES: Computer, power adapter, 
leads/plugs for connection to TV & cassette recorder, 
TV/computer switch, full instructions, and computing 
course manual. 

TS1000 $69.95 




ACCESSORIES FOR HlflUM Sinclair- 1 1000 and ZX81 



TS1016- Expands TS1000 from 2K to 16K of memory. (5 oz.) $49.95 



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• All characters and symbols 
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• Durable — formed with poly- 
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The JE681 Keyboard Mask provides users of the 
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each keypad on the keyboard. The mask has a rais- 
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feel and correctly position their fingers onto the 
keyboard. 

JE681 KEYBOARD MASK $9.95 each 



TS2040 - 32 Column thermal printer for TS1000 and ZX8 1 



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ZX81/1000* Keyboard 
Conversion Kit 




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KIT MOUNTED IN DTE- 
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TAN PANELS WITH 
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END PIECES. SIZE: 
14V4"Wx3V2"Dx3V 2 "H 

The JE682 Kit provides users of the ZX81 / 1000 series computers a full-size in- 
dustrial keyboard hook up to their computer. The JE682 Kit allows the use of 
either the full-size keyboard or the Sinclair/Timex Keyboard. The Kit also per- 
mits the simple disconnection of the Sinclair/Timex Keyboard for portable 
use. The JE682 Kit consists of a full-size industrial grade keyboard with 62 
keys, 2 p.c. boards, 18" ribbon cable, DIP socket and 4 rubber feet. The 
keyboard conversion kit can easily be mounted into the DTE-AK enclosure. 
This enclosure is large enough to contain the ZX81/1000 computer and the 
full-size keyboard together. A handy label representing the ZX81/1000 
keyboard layout is placed on the enclosure. 

JE682-AK Keyboard Conversion Kit $99.95 ea 

(WITH DTE-AK CASE - AS PICTURED) 

JE682 Keyboard Conversion Kit $59.95 ea. 

(WITHOUT DTE-AK CASE) 

DTE-AK CASE ONLY $49.95 each 



'ZX81/1000 is a trademark of Sinclair/Timex 



TIMEX 



Sinclair- software 



THE ORGANIZER 

An information storage program Store the names, addresses, 
phone numbers birthday and anniversary dates ol your Inends 
and business acqu.i 

Part No. 032000 $16.95 

THE HOME ASSET MANAGER 

A home inventory program that can be very valuable in case of 
uic.e 01 purchase 
description, price, serial number and model number 

Part No. 032009 $12.95 



VUCALC 

This program constructs, generates and calculates large tables 
for financial analysis, budget sheets, and proiections An 

immensely powerful analysis chart 

Part No. 031000 $19.95 

CHECKBOOK MANAGER 

A personal or business checking account program lo store and 
sort banking transactions On 90 mmule tape, up to 3.600 tran- 
sactions can be stored 
<_ Part No. 032003 $15.95 



ALL TIMEX SINCLAIR SOFTWARE AND TIMEWORKS SOFTWARE REQUIRE 16K OF MEMORY 

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WALL STREET 

A game of competitive financial speculation Limited dollars lo mvesl which will put you on Easy 
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Part No. TM 1 $1695 

STAR BATTLE 

inn from the Scions Realistic action and thinking game 
Part No. TM 2 516.95 



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California Residents Add 6'?% Sales Tax 
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THE FLIGHT SIMULATOR 

Take control of highly maneuveraWe li(,ht aircraft With controls, 
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landing 

Part No. 033002 $19.95 



SUPERMAZE 



scpdirtie 



Navigate your way inrough a three-dimensional maze 
doors, goto Dars. mamer siones aim ujmuass Te 
mazes Three dimensional graphs 
Part No. 034006 $14.95 



FROGGER 

Plays like the arcade game Hop the Irog over traffic, snakes, 
crocodiles and treacherous diving turtles before time runs out 

Part No. 034012 $17.95 



SUPER MATH 

Dnli yourself un addition, suotf action multiplication, and divi- 
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Part No. 033000 $14.95 



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Driving an automobile or playing a flight 
simulation game with a keyboard is 
just not natural. 



your computer. Although it is rugged and 
can be reasonably handled, it is mainly 
made up of CMOS gates which can be 
permanently put out of action by a small 
static discharge. When working with 
CMOS circuits, I make it a policy never 
to wear sweaters or synthetic clothing or 
to work around plastic sheets, carpet, 
dogs, cats, or kids. Kids do not usually 
carry a lot of static charge, but they do 
have a tendency to drag all your parts 
into the floor when you are not looking. 
Try to discharge any static before touch- 
ing the PC board. This can be done by 
touching a heavy metal object. Always 
use a high quality soldering pencil, pre- 
ferably a grounded type, to insure against 
voltage transients from the iron. 

Testing the Joystick 

Plug the new controller into your con- 
nector and turn on the computer. A for- 
ward movement of the stick should pro- 
duce a 'T'and a backward direction will 
produce a %" Left and right should pro- 
duce a "5" and "8" respectively. I wired 
the "fire" button to "9" because it was 
convenient, but you can wire it to the 
character you prefer. 

If you only get a blink of the cursor and 
no character, either you have shorted one 
of the matrix lines to each other or one of 
the switches in the joystick is stuck closed. 
If you get a wrong character, you have 
misconnected one ot the KB and D lines. 
Remove the controller from the con- 
nector; entry from the original keyboard 
should return to normal. 

The only big disadvantage to this ar- 
rangement is that a diagonal direction 
cannot be achieved. I feel, however, that 
with the combined use of the fire button, 
this function could be easily 
programmed. 

Rewriting Existing Programs for the New 
Joystick 

The improved operation of the flight 
simulation program was so dramatic that 
I decided to rewrite all of my graphic 
programs to respond to the cursor keys. 

My screen drawing program, "Sketch- 
pad," is now a real joy to use. The three 
year-old from next door now loves 
"Sketch-pad," but he would not even try 
it with the keyboard. The program is 
shown in Listing 1 for those of you who 
would like to try your artistic hand with 
the new joystick. The "fire" button is used 
to select between either erasing or draw- 
ing. Pushing the button causes the pixel 
to erase itself as it is moved. Then, by 
pushing the button again, drawing can be 



continued. This handy little feature allows 
you to erase any errors or move the pixel 
to another location to start another line. 

Listing 1. Sketch-pad program. 



54 



5 REM "SKETCH-PAD" 

10 CLS 

15 PRINT "DRAW" 

20 PRINT "Z=CLEAR" 

25 PRINT "USE FIRE BUTTON FOR ERASE" 

45 LET X=30 

50 LET Y=20 

55 IF INKEY$="9" THEN GOTO 135 

60 IF INKEY$="7" THEN LET Y=Y+1 

65 IF INKEY$="6" THEN LET Y=Y-1 

70 IF INKEY$="5" THEN LET X-X+l 

75 IF INKEY$="3" THEN LET X=X-1 

80 IF INKEY$="Z" THEN RUN 

85 PLOT X,Y 
115 UNPLOT X,Y 
120 PLOT X,Y 
125 GOTO 55 

130 IF INKEY$="9" THEN GOTO 60 
135 IF INKEY$="7" THEN LET Y-Y+l 
140 IF INKEY$="6" THEN LET Y=Y-1 
145 IF INKEY$="5" THEN LET X = X+1 
150 IF INKEY$="8" THEN LET X=X-1 
155 UNPLOT X,Y 
160 PLOT X,Y 
165 UNPLOT X,Y 
170 GOTO 130 



Most Basic programs use one or two 
methods to control the movement of the 
PRINT or PLOT command. This is 
usually done using the INKEYS function 
and usually lets some variable equal 
PEEK 16421. This location is the storage 
area of the value obtained from the key- 
board scan done after each TV frame. 
However, the code that is stored in this 
location is only a value that lets the com- 
puter know which section of the keyboard 
is being pressed. That is, the character 5 
would have its own value but the char- 
acters 6 through 9 would all have the 
same code since they are all located in 
the same keyboard section. This method 
is slightly faster, but will work with the 
cursor controls. The PEEK method will 
have to be replaced with the INKEYS 
function as in Listing 2. 

Listing 2. Rewriting the PEEK method 

100 LET X - PEEK 16421 

130 IF X=(239) THEN LET Y=Y+1 

Change To: 

130 IF INKEYS = (your character) THEN 
LET Y=Y+1 

Delete line 100 

You will find that the trouble of re- 
moving the case back and the soldering 
of the connector will be well worth the 
effort when you see how easily the graph- 
ics now respond. 

The $8.50 turned out to be a good 
investment. Efl 

July/August 1983 c SYNC 



NOW 

YOU CAN HAVE 

ALL THE ANSWERS 

With the most complete Sinclair software library available. 



DM IAN LOGAN 





izxeirx80zx§i 



UNDERSTANDING YOUR ZX81 ROM 

by Dr. Ian Logan 

SYNC Magazine said: "SYNC readers will recognize 
Dr. Logan as a ma|or ZX80/81 expert whose writings 
are well worthwile. Understanding Your ZX81 ROM is 
no exception. The book falls logically into five parts: 
a brief review of the Z80 CPU. next a qutck intro- 
duction to the internal arithmetic and number base 
manipulations; a discussion of the Z80 machine code 
instructions grouped by function, a detailed exam- 
ination of the relevant ports of the 8K ROM; Dr. Logan 
introduces machine code programming by treating it 
as an extension to Basic; and complete listings of the 
more important 8K ROM routines are given as well as 
the usual tobies of machine code language 
instructions, decimal-hexadecimal conversions, and 
keycodes. Understanding Your ZX81 ROM should be 
high on your list " Now available for only $14.95 

MACHINE LANGUAGE PROGRAMMING 
MADE SIMPLE 

Michael Roberts, SYNTAX Magazine wrote 
"I wanted to review this book because I'm the person 
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Machine Language would be a good addition to 
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analogies help make this langua 
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NOT ONLY 30 PROGRAMS; 

is a collection of programs for tb 

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THE COMPLETE TIME)t 

ZX81 ROM Disassembly {i*u$u3a& 
Dr Logan and Dr. Frank O'Hara how.sjMjmineO 
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This book is a must for the experienced programmer' 
L'Ordmateur Individuel (the leading French personal 
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MELBOURNE HOUSE SOFTWARE «&9 



2K To 4K RAM Upgrade 

—An Introduction To ZX/TS Hardware 

Randalls. Glldden 



Introduction 

Aside from the obvious fact that the TS1000 is an incredibly 
powerful computer for the money, it has a barebones simpli- 
city in its hardware design that invites the user to explore and 
learn the hidden secrets of its digital circuitry. This hardware 
project will upgrade your on-board 2K RAM to 4K (or more) 
for under $10 and provide you with the opportunity to learn 
something of the elegance of computer electronics, with 
(hopefully) minimal risk of destroying your computer in the 
process. 

Although this article applies to the TS1000 with 2K RAM, 
it will also work just fine with a ZX81 with the 2K RAM 
upgrade. (See J. Wayne Schneider's excellent article in SYNC 
2:4 for 2K expansion details). 

Hardware projects with the TS1000 are not really difficult 
since there are relatively few major components to deal with 
and the printed circuit board is laid out in a fairly logical 
fashion. It does, however, require more than just "cook book" 
knowledge to complete this project successfully — success 
being measured both by what has been accomplished and by 
what has been learned along the way. RAM expansion is a 
good example of a hardware modification that will give you 
exposure to some of the basic concepts of computer hardware 
design and function, and perhaps provide a foundation for 
further projects and experimentation. But most of all, I hope 
you will find that it is fun to get your hands on the circuits and 
make the computer do something new for you. 

Part 1 of this article deals with the theory needed to 
understand the circuit modifications that will be made. It 
assumes that you know a little about binary numbers and 
simple electronics. If you want to learn the theory without 
voiding your warranty (which happens if you open up your 
computer during the warranty period), just read Part 2 which 
describes the construction and testing of the RAM expansion. 
Those of you who already understand all the concepts in Part 
1 are excused to go immediately to Part 2. 

Parti 

1 ) Binary 

Since computer address and data lines are coded in binary, 
you need to know the binary system in order to understand 
how data is shuffled about in the TS1000. If you do not know 

Randall S. Glidden. M.D., 185 Chiswick Rd.. Brighton, MA 02135. 
56 



binary, take the time to learn it before you begin. 

2) Digital Circuits 

Electronically speaking, binary logic Ts and 0's can be 
represented by high and low voltages, respectively. In most 
digital circuits +5 volts = 1 and zero voltage (ground) = 0. 
This has been compared to a switch being either in the "on" 
or the "off" position; however, this is misleading. A digital 
logic zero should always be thought of as a wire connected to 
ground and not as a wire disconnected from voltage. 

Another way to look at this is that a logic 1 sources +5 
volts to a particular wire or device, while a logic sinks 
voltage coming from that device to ground. Obviously, if a 
wire is connected neither to +5 volts nor to ground then it 
will be unable to source or sink current. 

From thl^ noint on lrp(=»n thp> frillrwinrr in rv»Jrt/-1. 

, - r to ... ..«.,«. 

5 Volts = logic 1 = high. 
Ground = GND = Volts = logic = low 
These will be used somewhat interchangeably. 

3) TS1000/ZX81 Circuitry -Overview 

The circuitry of the TS1000 can be divided into the follow- 
ing components (Refer to the photograph in your TS1000 
Basic Programming): 

a) Power source and +5 voltage regulator with a bunch of 
capacitors to provide a constant, smoothed, 5V power 
supply. 

b) Z80A Central processing Unit (CPU): A 40 pin integrated 
circuit which performs all the "computing" functions. To 
make the Z80 ready to do Basic after you turn it on, it must 
receive operating instructions from the 8K ROM. 

c) 8K ROM: A Read Only Memory which provides, in a 
sequential order, all the commands required so that the CPU 
can provide Sinclair Basic to the user. The commands are 
"byte" sized (i.e., decimal values to 255) machine code 
instructions which occupy memory addresses through 8191. 

d) 2K RAM: Random Access Memory which is used for 
temporary' storage of the program and the operating system 
variables (used by the ROM and CPU). 

e) Sinclair Computer Logic chip: A conglomeration of 
logic gates and other circuitry which ties together the other 
components, generates the video display, provides circuitry 
for SAVE and LOAD, encodes the keyboard for the CPU, 
etc. 

f ) Miscellaneous stuff: VHF video modulator, clock circuits, 

July/August 1983 c SYNC 



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keyboard interface, expansion port, etc. 

The functioning of all these components is beyond the 
scope of this article, but we do need to discuss how the Z80 
CPU is tied in to the RAM and how to modify it to suit our 
purposes. 

4)Z80CPU 

Most of the 40 pins of the Z80 can be divided into three 
groups (see Figure 1): 

a) Control signals 

Since these are the most difficult to deal with conceptually, 
we will ignore most of them. Suffice it to say that these carry 
signals either to the CPU (and therefore telling it to do 
something) or away from the CPU (and telling another device 
to do or get ready to do something). Without the control 
lines, the CPU would sit i dly b y, not knowing what to do next. 

Let's consider RD and WR which are signals from the Z80. 
These can tell the RAM or ROM that the CPU wants either 
to ReaD something from memory or to WRite something 
(RAM only) into memory. The bar over the letters is read as 
"not WR," which means that during a write operation, when 
WR becomes active, a logic zero is present at that pin. I.e., if 
a device is to respond to that signal, it must be activated by a 
and turned off by a 1. 







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M WR- \ 


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b) Address Bus 

Sixteen separate, parallel lines (collectively called a bus) 
carry signals from the CPU to another device (RAM, ROM, 
etc.). They tell it the location of a particular byte of data. 
These lines are indicated by the abbreviations AO through 
A 15. The AO line represents the least significant bit (LSB) of 
a 16 bit binary number, and therefore it can have the decimal 
value 1 or 0. A 15 is the most significant bit (MSB) so, when it 
carries a 1, it has the decimal value 32768. Since all 16 lines 
can carry either a 1 or a 0, the address bus can code, in 
binary, any number from decimal to 65535. 

Transmission of an address along the address bus is done in 
a parallel fashion, i.e., if address 65535 is called for, then Ps 
appear simultaneously at all 16 of the address bus lines for a 
brief instant. Many of the address lines are connected to 
corresponding address pins of the memory devices, as you 
will soon see. 

cj Data Bus 

This is similar to the address bus in that it is a parallel set of 
lines which carry signals from the CPU. It differs in that it 
also carries data to the CPU (i.e., it is bidirectional). In 
addition, it has only 8 lines (DO through D7) instead of 16. DO 
is the LSB (equals or 1, decimal) and D7 is the MSB (equals 
or 128, decimal). So on the data bus, any number from to 
255 can be sent to or from the CPU. 

d) Other pins 

Besides a +5 volt and a ground pin, there is a clock input 



(marked $ ). This pin receives a 3.5 MHz pulse from the 
clock circuitry, thus providing the all important timing of the 
sequential steps the CPU must take, whether it is running a 
program or just sitting there with a K in the corner. 

5) RAM: The Toshiba 2016 

The TS1000 uses the 2016, a 24 pin, 2048 word x 8-bit, high 
speed static RAM. It can contain 2048 different bytes of 
memory or a total of 16384 different bits. It has the memory 
capacity of a two to three ton vacuum tube memory bank of 
the 1950s vintage and probably costs less than a single vacuum 
tube did back then! 

The set-up of most of the 24 pins is similar to that of the 
CPU: 1 1 address bus pins (AO-A10), 8 data bus pins (D0-D7), 
3 control pins, and +5 volt and ground pins. The 11 address 
lines will code for any number from to 2047; the 8 data 
lines, for to 255. 

— Figure 2. 2016 2K RAM 

24 



•4 ^ h 






D5 J 



+ 5V 



22 A9 
II WR 

12-AiO 

i^-RAMCS" 

17 



16 



-D4 
D3 



The three control inputs simply tell the RAM chip what to 
do. CS is the chip select and it is effectively the on/off switch 
for the chip. This pin is c onnected to a control line from the 
Sinclair Logic chip called RAM CS. As before, the bar over 
"CS" means that it is active when this pin is low— i.e., the chip 
is selected or enabled when CS is low. When the chip is not 

needed, a lopio 1 is nre<ipnt at C**\ anH nr»thina h-jn^nr 

Besides being turned off when CS = 1, the data bus lines 
will be in a high impedance state (also called tristate) at those 
times. This means that those lines are effectively disconnected 
from the rest of the circuitry— current will neither flow 
through nor from the data pins when CS=1. The tristate 
concept is important since most, if not all, of the data and 
address buses are shared by so many different components. 
This effectively keeps them isolated from each other. 

RD is the READ enable. When it is low, data from a 
particular location in memory is available to be placed on the 
data bus and thus READ by the CPU. WR is the WRITE 

Table 1. Truth table for 2K RAM chip 
(TMM-2016 or equivalent) 



C5 


TO 


WR 


Mode of Chip 


Condition of data pins 


1 


X 


X 


Not selected 
(turned off) 


High Impedence 
(tri-state) 








1 


READ 


Data out 






1 








WRITE 
WRITE 


Data in 
Data in 



1 = +5 volts, high 

= Ground (0 volts), low 

X = Does not matter; could be 1 or 



58 



July/ August 1983 c SYNC 








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s too' 






fe* 1 



to 01 



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C^'tf^^/lVlCf 



enable. When it is low, data coming into the data bus can be 
written into a specified memory address. Since you cannot 



. Table 2. Memory address decoding. 



klk 

Al3 

A12 

All 

A10 

A9 

A8 

A7 

A6 

A5 

ft* 

*3 
A2 

Al 

AO 



2 * ''=32768 
2 lk =l638U 



2 1X = 2048 
2 10 = 1024 

2 8 = 256 



2° = 6k 

2 5 = 32 

2 = 16 

2 3 = 8 

2 Z . k 

2 1 - 2 



Mentor) sddresses occupied H\ 

each 2K RAM chip, i.e.. 2<M* " 
bytes t(t-2(M"') or any binary 
combination A0-A10 



> ol d. ■> odln* tor K 2k Block*. 



Table 3. 74LS138 Truth Table. 



lit J PI IsiC Si 



t.:.\ 




... 




H 


A 


« 2 a 4 5 • 1 












: 


X 




X 


X 


X 


1 1 


L 1 1 1 


- 


A 


1 


X 


X 


X 


t 


1111 


111 


- 


S 


- 


5 


A 


A 


A 




L 1 1 1 


- 








1 











111 


L 1 1 1 


] 








1 







1 


1 1 


L 1 1 1 


2 


.0 





1 





1 





110 1 


L 1 1 1 


3 













1 




1110 


1 1 1 


k 








1 


1 








1 1 1 1 c 


1 1 1 


5 








1 


1 




1 


1 1 1 1 J 


1 1 


6 








1 


1 


1 





1111 


1 1 


7 


Q 





1 




1 


1 


1111 


1 1 





Us. high 
= Ground (0 volts), low, 
X = Does not matter; could be 1 or 



- Figure 3. 74LS138 1 of 8 decoder. 



inputs 



C-3 



Enables j G2B— 1 

I Or-* 

Out pin 

volts -^ 



O 



74LSI3H 



P-Vl 

— V3 \{ \ 
rU. V 4l 

JSLvs 

-5-V6 I 



60 



READ and WRITE data out of/into memory at the same 
time, the chip is set up so that WR must be high (i.e., inactive) 
when RD is low (active) in order for a READ to take place. 

For a WRITE into memory to take place, WR must be low, 
but (for reasons of simplifying hardware design) RD can be 
high or low. In fact, the TS1000 ties RD permanently to 
ground; READ and WRITE operations are thus based entirely 
on the condition of WRjand CS of course). See Table 1. 

In summary then, if CS is high, the 2016 is turned off ajid it 
does not matter what is present at WR or RD. When CS is 
low, a WRITE into memory what is present at WR or RD. 
When CS is low, a WRITE into memory will occur if WR is 
low, and a READ will occur if WR is high (since RD is always 
low anyway). 

6) The Decoder 

A RAM pack, such as the Sinclair 16K pack, consists of 
several separate memory chips wired together in parallel. 
From our examination of the 2016, it should be clear that in 
order to expand our on-board memory we must have some 
way of sequentially selecting the chips we add, just as the 
different RAM chips in a large memory pack are selected. 
This is done by a decoder circuit, a logic circuit which simply 
divides a large number of memory addresses among several 
discrete memory chips. In other words, suppose we have 
eight 2K RAM chips. We could have a total 16K of RAM if 
we had a circuit that would apportion that 16K into separate 
2K chunks. In a more global sense, the decoder circuits in the 
TS1000 decide which of the 65535 potential addresses are 
locations in RAM, ROM, or whatever. 

The TS1000 decoder is located in that giant Sinclair Logic 
chip, and basically does its work based on the condition of 
A14. The ROM is enabled if A14 = (i.e., to 16383, 
decimal), and the RAM is enabled if A 14 = 1 (i.e., addresses 
16384 and above). (A15 is used in the video display and 
prohibits use of the 32K memory block above 32767 without 
some special outside decoding circuits.) When RAM space is 
needed by the CPU, the decoder e nables th e on-board RAM 
by sending a "0" through the line RA M CS, which is tied to 
tne C5 pin ot the 2016. Since RAM C S is low a t any address 
between 16384 and 32767, we can use RAM CS to help select 
any additional chips we may put in that space. What we must 
do, however, is provide for further decoding of that 16K 
block. 

Table 2 shows the decimal representation of the value of 
each address line, A0-A15. If we are using 2048 byte chips 
that are all wired in parallel to A0-A10, all we have to do is 
use the status of the upper address lines (Al 1-A15) to decide 
for us which chip should be enabled for a specified location in 
memory. 

The bottom portion of Table 2 shows that eight different 
chips, or a full 16K, can be selected using just All, A12, and 
A 13 (since there are eight combinations of a 3-bit binary 
number). Since A14 is always 1 and A15 is always from 16K 
to 32K, we can ignore them and use just A11-A13. What we 
need is a circuit that will take a 3-bit binary number as input 
and give us eight different outputs that can be used to select 
our memory chips. Luckily someone invented the 74LS138! 

7)The74LS138 

The 74LS138 is a 16 pin IC that functions as a *T-of-8 
decoder/demultiplexer." The block diagram (Figure 3) and 
truth table (Table 1 ) give some idea of how it operates. As 
with the 2016, this chip must also be enabled to be functional. 
It differs in that there are three different enable inputs, two 
active when low (pins 4 and 5), and one active when high (pin 
6). The truth table shows that, unless pins 4 and 5 are low and 
pin 6 is high, the outputs at V0-V7 will all be high, regardless 
of the condition of the three inputs: A, B, and C. When the 

July/August 1983 c SYNC 



chip is enabled, different inputs at S, B, and C (from (XX) to 
111, binary) produce a logic at one of the eight outputs, VO- 
V7. 

Now, if we connect All, A 1 2, and A 13 to inputs A, B, and 
C, respectively, and then connect the "V" outputs sequentially 
to our 2K RAM chips, we will have our decoding problem 
almost so lved. To enable the 74LS138 itself we can use the 
RAM CS line from the logic chip and connect it to enable 
pins 4 and 5 (remember, active low). To keep the "high" 
enable high we can just permanently connect pin 6 to +5 
volts. To make matters even simpler, if you are only adding 
one or two extra 2K chips, you can skip the connection to 
A13, since this is a for the first four 2K blocks anyway. Just 
connect input C to ground, in that case, making it a permanent 
0. 

Congratulations! If you have made it through all that, you 
could probably do the memory expansion project without 
reading any further, since al l we have to do is connect the 
74LS138 to GND, +5 volts, RAM CS, All, and A12 on the 
TS1000 circuit board, and connect two of the 74LS138 output 
pins to the CS pins of two 2K RAM chips stacked on top of 
each other. All you really need to know now is the location of 
the necessary lines on the circuit board and some of the 
practical construction points. These will be covered in Part 2. 

Part 2 

Now we will dive into the actual construction details of our 
RAM expansion. Hopefully you are already familiar with 
which end of a soldering iron gets hot, and perhaps you 
already have some (or all) of the equipment listed below. 
Since it is a little tricky soldering connections directly to 
integrated circuit pins, I recommend that you buy an inex- 
pensive wire-wrapping tool and make the connections that 
way. Provide yourself with a clean, well lit work space, get 
together all the necessary materials, and have fun! 

Materials 

1) A 2Kx8 static RAM. Although I have discussed the 
Toshiba 2016 above, I recommend the Hitachi, HM 6116LP- 
4. JDR Microdevices, Inc. sells the 61 16LP-4 for $6.95 (at the 
time of this writing). You can get a 6116-4 (not LP, low 
power) for $4.95, but it uses slightly more power— a consider- 
ation if overheating is often a problem. The 2016 (TMM 
2016-200) is the cheapest 2Kx8 RAM on JDRs list, selling for 
a mere $4.15. It does, however, use more power than any of 
the 61 16s, but all the pin designations are exactly the same. 

Note that when you see a catalog listing of these chips you 
will see that the access times are listed in many cases. For 
example, a 6116-4 has an access time of 200 nanoseconds 
while a 6116-2 has an access time of 120 nanoseconds. The 
Z80 CPU uses about 900 nanoseconds to access a RAM chip, 
so it is not necessary to spend more money for the faster 
chips; better to get the low power RAM and save on power 
requirements instead. 

By the way, I recommend JDR as a source for IC chips 
because they always have a catalog type ad at the back of 
every issue of Computers and Electronics (formerly Popular 
Electronics), they have a toll-free number for charge card 
orders (800/662-6279; ( alifornia onlyf, their prices are as low 
as you are likely to find, and they ship fairly quickly. They do 
have a $10 minimum order, which is more than you will need 
to spend in parts for this whole project! But you can stock up 
on a few other parts to pad out your order. Their address is: 
JDR Microdevices, Inc., 1224 S. Bascom Ave., San Jose, CA 
95128. 

2) A 74LS138, l-of-8 decoder. $.55 from JDR or $.99 from 
Radio Shack. 

3} A Ifrpin solder-tail DIP IC socket. $.17 from JDR. 



Figure 4. Decoder wiring diagram. 

\ I 2 \ 1 1 

A 



- 



.- 



CS8 



Connection to Al.^ not 
needed if usinu less than 
2K RAM chips (dotted line). 
If A 13 is used, do not connect 
pin 3 to ground. 



:■: 









11 



3 C5.1 
i- 2 C$4 
UC55 

10C56 
I C57 U 



C52 C5l 

I o pin 18 oi 
2K RAM chips 



o volts 
(GND) 



4} 30 gauge wire-wrap wire. Radio Shack 278-500 series, or 
equivalent. 

5) Double-sided tape or rubber cement. 
o} Rosin-core solder. 

Tools 

1) A 15-25 watt fine-tipped soldering iron. 

2) A small wire-wrapping tool. Radio Shack 276-15700, or 
equivalent, 

3) A sharp, fine pointed knife, e.g., X-acto. 

4) A small Phillips-head screw driver. 

5) Needle-nose pliers. 

Construction Overview 

You will see from the schematic (Figure 4) that all we are 
doing is wiring the 74LS138 to the board and connecting two 
(or more) of its outputs to the CS pins of two (or more) 
stacked 2K RAM chips. The connections to the 74LS138 will 
be made by wire-wrapping directly to its pins and making a 
few solder connections to the TS1000 circuit board. To hold 
the chip in place we will use a 16-pin DIP socket with its pins 
removed and its socket holes enlarged with the X-acto knife 
accommodate the wire-wrapped IC pins. The 74LS138 in its 
socket will be attached to the board in the space between the 
RAM and the CPU using either double-sided tape or rubber 
cement. The RAM chips will be stacked on top of each other, 
with the upper chip pins bent inward slightly to make contact 
with the lower chip pins. The CS pins will be bent outward, 
and connected to the 74LS138 with wire-wrapping connec- 
tions. 

Step-by-Step Construction 

1 j Remove the TS1000 circuit hoard from the case. 

Turn the computer upside down so that the expansion port 
is pointed away from you. Remove the five Phillips head 
screws, three of which are under the lower two and upper left 
rubber pads. Remove the pads carefully and set aside. Note 
that the lower two screws are shorter than the upper three, 
and be sure you put them back that way when you are done. 
Remove the back and set it aside. 

2) Remove the circuit board. 

Remove the two screws holding the board in place, noting 
their position. Turn the board over and carefully pull the 
keyboard tails out of the board connectors. (D«> \^\ hend nr 
kink the tails in the process.) 

3) Locate the land marks. 

With board oriented in the same way as the photograph 
(Figure 5) locate the 2K RAM chip, the CPU, and the 
expansion edge connector strip. Since the TS1000 uses the 
same board as the ZX81, do not be surprised when you see 
"Sinclair ZX81" stamped in the upper right-hand corner! 
Between the CPU and the RAM chip is a space marked IC4a. 
This was used in many ZX8 1 s as half of the 1 K memory, since 



July/August 1983 c SYNC 



61 




Figure 5. TX /TS circuit hoard with added 74LS138 and 3 stacked 2K RAM 
chips, 

those had two 1028 x 4 bit chips instead of a single 1028 x 8 
chip. 

4) Wire the 74LS138. 

Practice making a few wire-wrap connections on some 
spare parts. Then you can make the connections shown in 
Figure 4. First connect pin 16 ( + 5 volts) to pin 6 (the 
permanent 1 enable), and then connect pin 3 (input C) to pin 
8 (ground) using short wire wrap connections. (Recall that for 
the first four RAM chips we do not need A 13, which would 
be input C. We will just hook it to ground, making it a 
permanent 0.) 

Prepare seven 2 to 3 inch lengths of wire-wrap wire with 
1/4" insulation stripped from one end and 1/2" stripped from 
the other. Wire-wrap the 1/2" ends to pins 1, 2, 4 and 5 
(together), 8, 14, 15, and 16. (If you are stacking more than 
one RAM chip, you will need additional wires at pins 13-9, as 
shown in the schematic.) 
5) Prepare the socket. 

With a pair of pliers pull all the solder-tail pins out of the 16 
pin DIP socket. They should pull right out. With the X-acto 
knife enlarge the socket holes wherever a pin with wire-wrap 
is to be placed, and then see if your wired 74LS138 will fit into 
it. You will probably have to bend the pins inward a bit to do 
this. You should get a nice snug fit so that the IC will not pop 

L7UI ~. v„.~ JW«v l vvmiWll JKJKJL pui UkMK, ^UllipUlCl UdCK LUgClIlCr. 

6) Solder the 74LS138 to board. 
Figure 6, Location of holes for solder connections. 

-RAMCS 




Labels correspond to those found on the TS1000 

or ZX81 circuit board. 



62 



You will need to make five solder connections to the 
circuit board. As long as you do not touch the tip of the 
soldering iron to the ICs on the board you should cause no 
damage while soldering, so I do not recommend you remove 
all four ICs. It is helpful to have your TS1000 operable during 
this part of the construction so that you can turn it on after 
each solder connection and see if it still works, as a solder 
short will yield a blank or broken screen. This makes trouble 
shooting much easier. 

With the power to the computer off, place each wire from 
the 74LS138 in turn into its appropriate hole as shown in 
Figure 6, and solder it in place, using as little solder as 
possible. (Hint — tinning the ends of each wire with solder 
beforehand allows two-handed soldering, rather than the usual 
"three-handed" method.) Be careful the solder has not shorted 
across to another circuit tracing— check each side of the 
board for this. After each soldered connection test the 
computer by hooking it to the TV and applying power— you 
do not need the keyboard hooked up to get a K cursor. If at 
any point the K does not appear after you have made a 
connection, do not panic. Just check the connection carefully 
and resolder if necessary. 

7) Stack the RAM chips. 

Take the RAM chip you are going to add, and orient it 
over the on-board RAM chip. Locate the dent at the top end 
of the chip so that it lies above the dent end of the board 
RAM chip. You will see that the pins of your upper chip 
probably do not make contact with the lower chip pins. Place 
the edge of the chip on a flat surface and apply gentle 
downward pressure to bend all the pins on one side inward 
slightly. Repeat this on the other side and try stacking the 
chip again. Continue bending the pins inward, a little at a 
time, until all the pins make firm contact with the pins of the 
lower chip. Since the RAM chips are wired in parallel, except 
for the CS pins; this snug fit is of the utmost importance for 
success. 

Now locate the CS pin (pin 18), and bend it outward so that 
it is at a right angle to the other pins. Now replace the chip in 
its protective foam for now and set it aside. 

Carefully remove the on-board 2016 RAM chip by alter- 
natively prying up at each end with a small QrrpwHHyer. Be 
careful not to bend the pins. Locate pin 18 again (CS) and 
bend it outward as you did with the chip to be added. Replace 
the 2016, with pin 18 sticking out sideways, out of its socket. 

8) Final connections and testing. 

Wire-wrap the wire from pin 15 of the 74LS138 decoder to 
pin 18 of the on-board RAM. Power up the computer and see 
if it works, now that the on-board chip is connected to the 
decoder. If it does not work, go to the "Trouble shooting," If 
it works, pat yourself on the back and then wire-wrap pin 18 
of the other RAM chip to the decoder pin 14, and stack the 
chip on top of the on-board chip. Be sure that all the pins are 
making firm contact with each other (except, of course, pin 
18). Although Figure 5 shows three 2K chips stacked together, 
your board should now look similiar. 

Apply power again and see what happens. After a delay of 
about 3-4 seconds you should see the K cursor appear. Now 
comes the moment of truth: reconnect the keyboard tails and 
check the memory RAMTOP setting by typing in: 

PRINT PEEK 16389*256-16384 

You should then see 4096, the amount of RAM available. If 
that is what you get, then pat yourself on the back again, have 
a beer, and go show your wife/husband/significant other the 
wonderful thing you have done. If you get 2048 that just 
means your added RAM chip is not making firm contact with 
all the pins; reposition it and try again. 
9 } Reassembly. 

After playing with your new 4K RAM a bit, you will 
probably want to anchor the added RAM chip to the board 

July/August 1983 £ SYNC 




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64 



chip either by applying double sided tape to its side or by 
gluing with a thin layer of rubber cement. This will keep the 
chip from popping off after reassembly. I would advise against 
using epoxy or super glue, since it is possible you may want to 
remove or adjust the placement slightly in the future without 
the aid of a hammer and chisel. 

Some people with much CMOS expertise may wish to 
solder the two chips together. This is dangerous to the life of 
your RAM chips unless you have had considerably more 
experience than most in doing this. You must use a soldering 
iron with a grounded tip and be a bit more cavalier than I am 
to attempt it; so do so at your own risk! 

Now attach the 74LS138 socket to the board using double 
sided tape or rubber cement. Make sure none of the IC pins 
are extending through the socket; this could cause a short. 
You may want to insulate the socket with some electricians 
tape to safeguard against this. 

Try to tuck the wires from the decoder out of the way, 
since the keyboard tails will be lying directly over it when the 
computer is reassembled. 

Now, make sure the added RAM still works, and the replace 
the circuit board in the case and close up. Be sure you use the 
proper screws. Reattach the rubber feet, using rubber cement 
if needed. 

Beyond 4K 

If you have your circuit board mounted inside some kind of 
big keyboard enclosure with enough room, you can stack up 
to eight chips {in theory at least — I have stacked only three). 
Just bend out pin 18 of each chip and wire-wrap one of the 
other output pins from the decoder to it. If you do this, I 
would especially advise using the 6116-LP4s, keeping the 
power requirements to a minimum. Unfortunately, there is 
only room for one extra chip under the hood of a standard 
TS1000. 

Trouble Shooting 

The following problems are the ones you will most likely 
encounted. 

solder shorts and for poor solder connections. Are all the 
solder connections made in the correct holes? Also beware of 
steel wool dust — a common work shop containment. It can 
microscopically short across some of the closely spaced 
traces. 

Make sure you wired the 74LS138 correctly and that none 
of the wire-wrap connections are shorting each other out. 
(You did not wire the chip backwards, did you?) Also make 
sure you wired the decoder to pin 18 of the RAM chips. 

If all else fails, it is possible you have a bad 74LS138; get 
another and try again. (This does not happen very often.) 

2) Can only get 2K of RAM. Make sure all the RAM pins 
are making firm contact with each other. Try bending them 
all in a bit more. Make sure that pin 18 of one RAM is not 
touching that of the other RAM. See that the connections 
from the decoder to the chips are good. 

3) If you have any other trouble please send me a descrip- 
tion of your problem along with a self-addressed stamped 
envelope, and I will try to help you if I can. 

Conclusion 

Well, that is about it. I hope that your RAM expansion has 
been successful, and that you will now want to try your hand 
at other hardware projects. Having an expansion board is the 
best way to take on serious hardware design, since all con- 
struction is done on separate boards, thus posing less risk to 
your main computer circuits. 

I welcome any comments, constructive or otherwise, from 
S YNC readers. "V 

July/August 1983 • SYNC 



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Stringing along with the ZX81 



Paul J. Wentink 



The DATA-READ statement is the 
basic computer command for the efficient 
storage and use of data comprised of 
many values (bulk data) where data is to 
be used repetitively in a program or where 
data is to be retained for successive com- 
puter runs. Such data might consist of 
names and addresses, names and phone 
numbers, football scores, degree days, 
inventory part numbers, star brightness 
intensity, input from an RS232 port, and 
on and on and . . . 

As we are aware, the ZX81 does not 
include these statements. The ZX81 Basic 
Programming manual by Steven Vickers 
suggests the use of LET X=N type state- 
ments to duplicate DATA statements. 
This, unfortunately, requires the extensive 
dedication of memory for data storage 
except for short programs. Another 
method of achieving a ZX81 DATA- 
READ capability would be through ma- 
chine ianguage. This wuuid require a vciy 
thorough knowledge of the Z80 CPU 
assembly language. There is, however, a 
method of simulating DATA-READ state- 
ments on the ZX81 using string state- 
ments, slicing, and the LEN/VAL 
functions. This method does not require 
the use of machine language nor does it 
require excessive memory. Furthermore, 
it can be easily mastered if the use of 
string statements as presented in the 
ZX81 Basic Programming manual is 
understood. 

The proposed method consists of enter- 
ing data as a string statement, slicing the 
characters from the string which make up 
a data-set, converting the sliced substrings 
to a numerical value, if necessary, and 
then using these substrings as program 
variables. 

The ZX81 DATA-READ simulation tech- 
nique is generally developed in accordance 
with the following steps: 

Step I . Enter all data in a string statement 
(LEI XXX") so that each data-set 

within the string can be identified repetitively 



Paul J, Wentink. 36102 S.E. 44th St.. Fall City, 
w \ 98024. 



by character position within the string. 

Step 2. Set up an array which will permit 
each data-set to be assigned a unique address 
in the array as it is sliced from the string, or 
originate statements which will selectively 
slice data-sets from the string to be used di- 
rectly as program variables. 

Step 3. Read data-sets from the array or 
string as applicable, convert data to numeric 
values if necessary and use as program 
variables. 

Since data entered in a program using this 
method is always directly addressable, there is 
no need for the RESTORE command which is 
usually associated with Basic DATA-READ 
commands. 

To demonstrate the ZX81 DATA-READ 
simulation technique, five programs are pre- 
sented of varying complexity showing first 
the DATA-READ program in Basic Language 
which is not usable with the ZX81 Computer, 
and then equivalent programs written for use 



W I 111 11 IC J^WOl 



1U£1 



llgS 1/-L lillUUC,!! 



IE are all equivalent programs consisting of a 
data statement containing a number of data- 
sets from which data is read and then used in a 
simple arithmetic calculation. Program List- 
ings 2A through 2C are all equivalent pro- 
grams demonstrating a ZX81 DATA-READ 
simulation for data which is NON-NUMER- 

Listing 1A. Conventional Basic 
READ-DATA Program 



05 REM LISTING 1A 

10 READ A.B.C.D 

20 PRINT A+B,C+D 

30 DATA 5,10,15,20 



15 



35 



IC. Program Listings 3 A through 5B are a 
series of three similar programs of increasing 
complexity wherein a data-set counting pro- 
gram tallies the number of times a data-set of 
like value occurs in a data statement. 



Program 1 

Listing 1A is a program written in con- 
ventional Basic using DATA-READ state- 
ments which cannot be executed on a ZX81 
Computer. 

Listing IB is a program, equivalent to list- 
ing 1A, which can be executed on a ZX81 
Computer. The program simulates a DATA- 
READ capability by entering the data as a 
string statement with all data-sets expressed 
as two characters separated from other data- 



Listing IB. 

ZX81 Simulation of DATA-READ Statement 

Using a Fixed Siz:e Addressable Array 



05 REM LISTING IB 

10 LET A$="05,10,15,20," 

20 DIM A{4) 

30 LET X = l 

40 FOR J = l TO 4 

50 LET Y = X+1 

60 LET A(J)=VAL A$(X TO Y) 

70 LET X=X+3 

80 NEXT J 

90 PRINT A(l)+A(2) ,A(3)+A(4) 



15 



07 90T 



35 



sets with commas for visibility (line 10). 

An array is then dimensioned to accept the 
data-sets so that each can be addressed by 
name when used as a program variable (line 
20). The data is sliced from the string and 
entered by value into the array (lines 30-80). 
Numerical calculations are then made using 
the data as addressed within the array (line 
90). 

Listing IC is the same program as Listing 
IB except that the array is not dimensioned for 
a fixed size but is set up equal in size to the 
number of data-sets existing in the program. 



66 



July/August 1983 ° SYNC 



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Listing 1C. ZX81 Simulation of DATA-READ 

Statement Using a Variable Si/.e Addressable 

Array 

05 REM LISTING 1C 

10 LET A$="05,10,15,20," 

20 DIM A(LEN A$/3) 

30 LET X=l 

40 FOR J = l TO LEN A$/3 

50 LET Y=X+1 

60 LET A(J)=VAL A$(X TO Y) 

70 LET X=X+3 

80 NEXT J 

90 PRINT A(l)+A(2) ,A(3)+A(4) 




Each data-set, again, is expressed as two 
characters separated by a comma. Thus the 
array size must equal the total number of 
characters entered into the data string divided 
by 3 or LEN A$/3 (line 20). Since the size of 
the array will now adjust to the number of 
data-sets in the data string, the program loop 
entering the data into the array must likewise 
vary in length. This is accomplished by enter- 
ing LEN A$/3 into the loop command (line 
40). 

Listing 1 D is the same as Listing 1C except 
that new data has been added to the program 
in a new string command (line 901 ), the origi- 
nal A$ command has been adjusted to include 
the new B$ data (line 990) and the variable 
size array has accepted the new data without 
revision to the program. Thus new data has 
been added without need to re enter previous 
data or making any program deletions. It 
should be evident that additional new data en- 
tries can oe made in like manner by entering 
up to 26 new data strings of any length, i.e.. 
CS,D$, etc, and then including those strings 
in line 990. For example: 

900 LET A$= M 05,10,15,20," 

901 LET B$=" 2 5,30, 35, 40," 

902 LET C$-"45,50," 

903 LET D$="55,60,65,70,75,80,85," 
990 LET A$=A$+B$+C$+D$ 

999 GOTO 20 

Listing IE is the same program as Listing 
IB except that the data is not addressable 
within an array but is rather sliced from the 
data string and used directly as substrings as 
program variables. 

Program 2 

Listing 2 A is a program show in the ZX8I 
BASIC Programming manual as an example of 
ZX81 incompatibility with conventional 
Basic DATA-READ statements. 

Listing 2B is a program equivalent to List- 
ing 2A which can be executed on a ZX81 
Computer. The simulation of a ZX81 
DATA-READ program follows the same 
technique as explained for Listing IB except 
that the data is non-numeric and can therefore 
be used as a program variable as entered in the 

68 



Listing ID. ZX81 Simulation of DATA-READ 
Statement Using a Variable SUe Addressable 
Array with New Data Addition 

05 REM LISTING ID 

10 GOTO 900 

20 DIM A(LEN A$/3) 

30 LET X = l 

40 FOR J=l TO LEN A$/3 

50 LET Y = X+1 

60 LET A(J)=VAL A$(X TO Y) 

70 LET X = X + 3 

80 NEXT J 

90 PRINT A(l) + A(2) ,A(3)+A(4) , 
A( 5)+A(6),A(7)+A(8) 

100 STOP 

900 LET A$="05,10, 15,20, " 

901 LET B$="25,30,35,40," 
990 LET A$=A$+B$ 

999 GOTO 20 



15 
55 



3 5 
75 




Listing IE. ZX81 Simulation of DATA-READ 

Statement Using Data Directly Addressable within 

the Data String 

05 REM LISTING IE 
10 LET A$="05,10,15,Z0," 
20 PRINT VAL A$fl TO 21 + VA! A<{4 to k) i 
VAL A$(7 TO 8)+VAL A$(10 TO 11) 




Listing 2A. Conventional Basic 
DATA-READ Program 



05 REM LISTING 2A 

10 REM THIS PROGRAM WILL NOT .WORK 

IN ZX81 BASIC 
20 DIM M$(12,3) 
30 FOR N=l TO 12 
40 READ M$(N) 
50 NEXT N 

60 DATA "JAN" ,"FEB" ,"MAR" ,"APR" 
7 DATA "MAY"," J UN" ," JUL", "AUG" 
80 DATA "SEP" ,"0CT" ,"N0V" ."DEC" 

string without need tor VAL function conver- 
sion. It should be noted that the commas used 
in the data string (line 10) are used only for 
making the data readable. For computer pur- 
poses, the commas as shown serve no purpose 



Listing 2B. ZX81 Simulation of DATA-READ 
Statement Using a Fixed Si/e Addressable Array 
with Non-Numeric Data 

05 LISTING 2B 

10 LET D$="JAN,FEB,MAR,APR, 
KAY, JUN, JUL, AUG, 

SEP, OCT, NOV, DEC," 

20 DIM M$(12,3) 

30 LET X=l 

40 FOR N=l TO 12 

50 LET Y=X+2 

60 LET M$(N)=D$(X TO Y) 

70 LET X=X+4 

80 NEXT N 

90 FOR N=l TO 12 

100 PRINT TAB ( 5*N ) -3 ;M$ ( N ) 

110 NEXT N 



JAN 



FEB 



MAR 



APR 



MAY 



JUL 



JUN 



AUG 



SEP 



OCT 



NOV 



DEC 



Listing 2C. ZX81 Simulation of DATA-READ 
Statement Using a Fixed Si/.e Addressable Array 
with Non-Numeric Data and Array Content Print- 



05 REM 


LISTING 2C 


10 LET 


D$="JAN,FEB,MAR,APR, 




MAY, JUN, JUL, AUG, 




SEP, OCT, NOV, DEC," 


20 DIM 


M$(12,3) 


30 LET 


X = l 


40 FOR 


N=l TO 12 


50 LET 


Y = X + 2 


60 LET 


M$(N)=D$(X TO Y) 


70 PRINT "M${";N;")=";M$(N) 


80 LET 


X = X + 4 


90 NEXT N 



M$(1)=JAN 
M$(3)=MAR 
M$(5)=MAY 

M$(7)=JUL 
M$(9)=SEP 

M$(11)=N0V 



M$(2)=FEB 

M${4)=APR 

M$(6)=JUN 

M$(8)=AUG 

M$)10)=0CT 

M$(12)=DEC 




and could be deleted, However, it is possible 
to use such characters as data recognition 
Hags. In this ease they would be required. 

Listing 2C is the same program as Listing 
2B except that the data array is printed out as 

July/August 1983 4 SYNC 



the data array loop is executed. This program 
routine is useful to display the contents of the 
array but does not serve any program need. If 
the print statement {line 70) is not executed, 
the data will still be entered in the array as 
program variables. 

Listing 3A. Conventional Basic DATA-READ 
Program. . 

05 LISTING 3A 

10 DIM C(2) 

20 LET C(1)=0 

30 LET C(2)=0 

40 READ A 

50 IF A=-l THEN 80 

60 LET C{A)=C(A)+1 

70 GOTO 40 

80 PRINT C(UC(2) 

900 DATA 1 ,1 ,2,1 ,1 ,2 , 2 ,1,1,1,-1 




Program 3 

Listing 3 A is a program written in con- 
ventional Basic using DATA-READ State- 
Listing 3B. ZX81 Simulation of DATA-READ 
Statement for Single-subscripted Variable Arrav 
in Data Count Program. 

05 LISTING 3B 

10 DIM C(2) 

20 LET C(1)=0 

30 LET C(2)=0 

40 LET C$ = "l ,1 .2,1 ^ 1 ,2,2,1 ,1,1 ," 

45 PRINT "LENGTH OF C$=";LEN C$,, 
"DATA COUNT =" ;LEN C$/2 

50 LET D=2 

60 LET A=l 

70 LET X=l 

75 FOR N=A TO LEN C$/D 

80 LET J=VAL C$(X) 

85 LET C(J)=C(J)+1 

90 LET X=X+2 
100 NEXT N 
110 PRINT 

120 PRINT "CO)" ,"C(2)" 
130 PRINT C(l) ,C{2) 



LENGTH OF C$=20 
DATA COUNT=10 



C(D 
7 



C(2) 

3 



ments which cannot be executed on a ZXX1 
Computer. 

Listing 3B is a counting routine using a 
single-subscripted variable array. The array 
diagram is shown in Figure 1 . As shown by the 
diagram, each data set consists of one vari- 
able, "A". A running total is made of data- 
sets equal in value to 1 or 2 which are ad- 
dressed as variables C(l) and C(2) re- 
spectively. Thus, in the data string (line 40) 
there is a total oi 20 characters. There are 10 
data-sets, 7 of which are equal to 1, and 3 of 
which are equal to 2. The arrangement of data 
in the DATA STRING is as follows: 40 LET 
C$ 'A, A. A, etc" 

Figure 1. Array Diagram for Listing 3B 



A=l 


C(D 


A = 2 


C(2) 



Program 4 

Listing 4 A is a program written in con- 
ventional Basic using DATA-READ state- 
ments which cannot be executed on a ZX81 
Computer. 

Note: Lines are numbered as shown to save 
memory for IK RAM. 



Listing 4A. Conventional Basic DATA-READ 
Program 

05 REM LISTING 4A 

10 DIM C(3,3) 

20 FOR Y=l TO 3 

30 FOR Z=l TO 3 

40 LET C(Y,Z)=0 

50 NEXT Y 

60 NEXT Z 

70 READ J.K 

80 IF J=-l THEN 110 

90 LET C(J,K)=C(J,K)+1 
100 GOTO 70 

110 PRINT C( 1 ,1 ) ,C ( 1 ,2),C(1 ,3) 
120 PRINT C(2,1),C(2,2),C(2,3) 
130 PRINT C(3,1),C(3,2),C(3,2) 
900 DATA 1,2,1,1,2,1,2,2,3,3,3,1,2,3, 
1 ,3,1,3,2,1 ,3,1, 3,3,3,3,-1,-1 



1 


1 


2 




2 


1 


1 




2 
3 


P 



Listing 4B is a counting routine program 
equivalent to Listing 4A using a double- 
subscripted variable array. The array diagram 
is shown in Figure 2. A running total of all 
like data values are entered and counted in 
the array addresses as shown in the array 
diagram. 



Listing 4B. ZX81 Simulation of DATA-READ 

Sum- merit for Double-Subscripted Variable Array 
in Data Count Program. 



1 REM LISTING 4B 

2 DIM C{ 3 ,3) 

3 FOR Y = l TO 3 

4 FOR Z=l TO 3 

5 LET C(Y,Z)=0 

6 NEXT Z 

7 NEXT Y 

8 LET C $ = " 1 , 2 ; 1 , 1 ;2,1 ;2,2;3,3; 

3 , 1 ; 2 , 3 ; 1 , 3 ; 1 , 3 ; 2 , 1 ; 

3 , 1 ; 3 , 3 ; 3 , 3 ; " 
10 PRINT "DATA-SETS =" ;LEN C$/4 
20 LET J=l 

30 FOR N=l TO LEN C$/4 
40 LET K=J+2 
50 LET Y=VAL C$(J) 
60 LET Z=VAL C$(k) 
70 LET C(Y,Z)=C(Y,Z)+1 
80 LET J=J+4 
90 NEXT N 

95 PRINT C(l,l) ,C(1,2) ,C<1 ,3) 

96 PRINT C(2,1),C(2,2),C(2,3) 

97 PRINT C(3,1),C(3,2),C(3,3) 



DATA-SETS 


= 13 


1 


1 


2 




2 


1 


1 




2 


i 


3 




/rf/97 





Figure 2. Array Diagram for Listing 4B. 




J*/13j* 





B = l 


B=2 


B = 3 


A = l 


C(l,l) 


C{1,2) 


C(l,3) 


A = 2 


C(2,l) 


C(2,2) 


C{2,3) 


A = 3 


C(3,l) 


C(3,2) 


C(3,3) 





July/August 1983 c SYNC 



69 



Each data-set consists of two data values (A 
and B), a data separating comma and a closing 
semi-colon. Thus in the data string (LINE 8) 
there are 13 data- sets consisting of 4 string 
characters each for a total string length of 52 
characters (4 X 13 = 52). The data-set length 
for program commands (line 10 & line 30) is 
then LEN C$/4. The arrangement of data in 
the DATA STRING is as follows: 8 LET 
e$= M A f B;A,B;A,B; etc." 



Program 5 

Listing 5A is a program written in con- 
ventional Basic using DATA-READ state- 
ments which cannot be executed on a ZX81 
Computer. 



Listing 5A. Conventional Basic DATA-READ 
Program. 



05 REM LISTING 5A 

10 DIM X(2,3) 

20 DIM Y(2,3) 

30 FOR 1=1 TO 2 

40 FOR J= 1 TO 3 

50 LET X(I ,J)=0 

60 LET Y(I,J)=0 

70 NEXT J 

80 NEXT I 

90 READ A,B,C 
100 IF A=-l THEN 180 
110 IF A=l THEN 150 
120 LET X(1,B)=X(1,B)+1 
130 LET X(2,C)=X(2,C)+1 
140 GOTO 90 

150 LET Y(1,B)=Y(1,B)+1 
160 LET Y(2,C)=Y(2 f C)+l 
170 GOTO 90 
180 FOR 1=1 TO 2 
190 FOR J*l TO 3 
200 PRINT X(I ,J),Y(I ,J) 
210 NEXT J 
220 NEXT I 

900 DATA 0,1,2 

901 DATA 1,2,3 

902 DATA -1,0,0 




Listing 5B is a counting routine program 
equivalent to listing 5 A using double-sub- 
scripted/multi-dimensional array. The array 



listing 5B. ZX81 Simulation of DATA-READ 

Statement for Single-Subscripted/Multi- 

Dimensional Variable Array in Data Count 

_ — Program 



1 REM LISTING 5B 

2 LET A$="0,l,2;l,2,3; 

3 DIM X(2,3) 

4 DIM Y(2,3) 

5 FOR 1=1 TO 2 

6 FOR J=l TO 3 

7 LET X(I,J)=0 

8 LET Y(I,J)=0 

9 NEXT J 

10 NEXT I 

11 LET D=0 

12 LET L=l 

13 FOR N=l TO LEN A$/6 
15 LET S = VAL A$(L) 

17 FOR J=l TO 2 

19 LET OVAL A$(L+D+2) 

21 IF S = l THEN GOTO 27 

23 LET X(J,C)=X(J,C)+1 

25 GOTO 29 

27 LET Y(J f C)=Y(J,C)+l 

29 LET D=D+2 

31 NEXT J 

33 LET D=0 

35 LET L = L+6 

37 NEXT N 



IK RAM: 



FOR IK MEMORY ENTER EACH OF THE 
FOLLOWING LINE 39 ENTERIES IN 
SUCCESSION TO DISPLAY ALL MATRIX 
VALUES OF THE ARRAY, 



40 FOR 1=1 TO 2 

50 FOR J = l TO 3 

60 PRINT X(I,J),Y(I,J) 

70 NEXT J 

80 NEXT I 



39 PRINT X(1,1),X(2,1),Y(1,1),Y(2,1) 
RUN (ENTER) 

39 (ENTER) 

39 PRINT X(1,2),X(2,2),Y(1,2) , 

RUN (ENTER) 



1 


% 


$ 


1 





t 


P 


I 


1 


i 


t 


i 


0/80 . 





39 (ENTER) 

39 PRINT X(1,3),X(2,3),Y(1,3), 

RUN (ENTER) 




Note for 16K RAM; For 16K. memory fol- 
low line 37 with lines 40 through 80. IK 
memory will accept 16K program but mem- 
ory will fill with a report 4/60 before the entire 
array is printed. 



Note: For 16K RAM all line numbers may 
be entered with addition of a trailing 0. 



diagram is shown in Figure 3. A running total 
of like data values are entered and counted in 
the array addresses as shown in the Figure 3 
matrix. Each data-set consists of three data 
values (A,B,C), two separating commas and a 
closing semi-colon. Thus in the data string 
(line 2) there are 2 data-sets consisting of 6 
string characters each for a total string length 
of 12 characters (6X2 = 12). The arrange- 
ment of data in the DATA STRING is as fol- 
lows: 

2 LET A$ = 'A,B,C;A,B,C;A,B,C; etc 
Applying this method of simulating 



DATA-READ statements with the ZX81 
should present no problem, provided the 
demonstration programs are followed line by 
line and the technique of string slicing is un- 
derstood. The only major difficulty which 
may be encountered is in actually slicing the 
data from the string. For example, if a non- 
umeri character is included in data which is 
to be converted to a numeric expression such 
as a comma, the program will not run. Of 
course in this case an error code will be dis- 
played (C/xx) upon execution of the program. 
Sliced data can be checked for correctness. 



Figure 3. Array Diagram for Listing SB. 





B=l 


B = 2 


B = 3 


C=l 


C«2 


C = 3 


A=0 I X{1 ,1) 


1(1 nl) 


X(l ,3) 


X( 2,1 ) 


X(2,2) 


X(2,3i 


A=l J Y( 1 ,1) 


Y(l ,2) 


Y(l,3) 


Y(t.l) 


Y{2,2) 


Y(2,3) 



70 



July/August 1983 Q SYNC 



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however, b\ simply executing a print com- 
mand which displays the sliced data prior to 
its use as a variable. The check is made during 
the writing of the program by entering a 
command to print the sliced data, running the 
program, checking the data for accuracy, de- 
leting the data print command and then pro- 
ceeding with the writing of the remainder of 
the program. For example, the following data 
slicing check could be used for program List- 
ing IB after writing line 50: 

Step 1: Enter new line. 
55PRINTA$(XTO Y) 

Step 2: Enter new line. 
56 PRINT VAL A$(X TO Y) 

Step 3: RUN program. 

Step 4: Check displayed data for accuracy. 
Correct slice commands if necessary. 

Step 5: Delete lines 55 and 56. 

Step 6: Continue writing program. 

Other Uses of This Technique 

Use of the proposed ZX81 string statement 
technique is not limited to simulating 
DATA-READ statements. This method can 
be used equally well to simulate other Basic 
Language statements which cannot be exe- 
cuted directly on the ZX81 Computer. 

Program Listing 6A shows a Basic program 
using an ON X GOTO N,N,N statement 
which cannot be executed on the ZX81. 



Listing 6A. Conventional Basic ON X GOTO 
n,n,n. Program 



05 REM LISTING 6A 

10 LET X= INT (RND*6) + 1 

20 PRINT X ; " # I S THE RANDOM NUMBER" 

30 PRINT 

40 ON X GOTO 100,200,300,400,500,600 
100 PRINT "THE RANDOM NUMBER IS 1" 
150 GOTO 700 

200 PRINT "THE RANDOM NUMBER IS 2" 
250 GOTO 700 

300 PRINT "THE RANDOM NUMBER IS 3" 

350 GOTO 700 

400 PRINT "THE RANDOM NUMBER IS 4" 

450 GOTO 700 

500 PRINT "THE RANDOM NUMBER IS 5" 

550 GOTO 700 

600 PRINT "THE RANDOM NUMBER IS 6" 

700 PRINT "END" 



X IS THE RANDOM NUMBER 

THE RANDOM NUMBER IS X 
END 



For the TS1(XX)/ZX81 Specify 16K or 64K RAM 



MMIAHuiul BDLSarc both: 

• MENU DRIVEN 

• URI TTKX ENTIRELY IN MACHINE LANGUAGE 

• SELF STARTING with automatic reset oframtop 

\\ Ik-ii hnih j >n grains arc loaded, you access one menu from the other with a 
single key. I Jolli U >I ).\M;md Ml )LSuiv accompanied I>\ a maimalamd for easy 
instruction, each program comes with a full demonstration program. 



USED INDIVIDUALLY, EACH PROGRAM IS A STRONG AND 

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FOR EDITING 6 HANDLING YOUR OWN BASIC PROGRAMS. 



s ohais mnjs 



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a memory chart of the BASK 
program area. I ODAB will occupy 
1430 b\ {• 



At the touch of a key, your BASK 
program listing will scroll up the 
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72 



Listing 6B. ZX81 Simulation of ON X GOTO 
n,n,n Statement 



05 REM LISTING 6B 

10 LET X=INT (RND*6)+1 

20 PRINT X; N #IS THE RANDOM NUMBER" 

30 PRINT 

40 LET A$ = "100, 200, 300, 400,500, 600," 

50 LET L = l 

55 FOR N=l TO LEN A$/4 

60 LET S=VAL A$(L TO L+2) 

65 PRINT "CYCLE NUMBER*" ;N 

70 IF N=X THEN GOTO S 

80 LET L = L + 4 

90 NEXT N 
100 PRINT "THE RANDOM NUMBER IS 1" 
150 GOTO 700 

200 PRINT "THE RANDOM NUMBER IS 2" 
250 GOTO 700 

300 PRINT "THE RANDOM NUMBER IS 3" 

350 GOTO 700 

400 PRINT "THE RANDOM NUMBER IS 4" 

450 GOTO 700 

500 PRINT "THE RANDOM NUMBER IS 5" 

550 GOTO 700 

600 PRINT "THE RANDOM NUMBER IS 6" 

700 PRINT "END" 



Note: To have program recycle enter the 
-i following lines: 

710 PAUSE 125 
720 CLS 
730 GOTO 10 



CYCLE NUMBER N 

THE RANDOM NUMBER IS X 

END 

0/700 



Listing 6B, however, shows the equivalent 
program structured for execution on the ZX81 
using the same string statement technique 
previously described. The program generates 
a random number which is compared to the 
value of the first character of a data-set in the 
data string (line 40). When the string charac- 
ter value is read which equals the value of the 
random number, the remainder of the selected 
data set is also read to provide a GOTO line 
address. That line address then executes a 
print command which identifies the value of 
the random number. It should be noted that 
although Listing 6B is to demonstrate an ON 
X GOTO N,N statement, line 70 could exe- 
cute any ZX81 command (PRINT, STOP, 
LET, etc). 

It appears, then, that the ZX81 has lots of 
Basic capability if you can use your pro- 
gramming imagination and just keep 
STRINGING ALONG WITH THE ZX81.H 



July/August 1983 c SYNC 




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RUNning with Reduced RAM Robert d. Hartung 



For most of us, the anticipation of be- 
ing able to write extended programs 
when we first plugged in our new 16K 
RAM pack was soon somewhat tem- 
pered by the waiting out of the monot- 
onous count at the end of every SAVE 
and LOAD. Also, functions such as CLS 
and NEW take much longer. 

Without connecting and disconnect- 
ing the RAM pack, the advantages of a 
smaller RAM may easily be regained by 
changing the address of RAMTOP for 
any program which requires less than 
3. IK RAM to RUN. Simply set 
RAMTOP below this limit by entering 
as direct commands (without line num- 
bers) one of the following sets, with the 



16K RAM plugged in: 



For IK (17408): 
POKE 16388,0 
POKE 16389,68 
NEW 



For2K (18432) 
POKE 16388,0 
POKE 16389,72 

NEW 



Robert D. 

14522. 



Hartung PO Box 125. Palmyra, NY 



For 3K (19710) 
POKE 16388, 254 
POKE 16389,76 

NEW 

When you have set the RAMTOP ad- 
dress to 19710 (which was POKEd in as 
76*256 + 254), your computor will be- 
have as though it has only 3. IK RAM. 
(These addresses are valid only for 8K 
ROM). You can also LOAD programs 
into this 3. IK which have previously 
been SAVEd to tape in 16K, provided 
they do not exceed the RAM limit as it 



is now set. They may then be SAVE 
back to tape in 3K, saving time and wear 
and tear on your recorder — and your pa- 
tience. The reduced RAM will remain in 
effect until the computor is powered- 
down or RAMTOP is reset. 

If tape listing does not LOAD because 
it was SAVEd with strings or variables 
or DIMs defined in memory, it might fit 
into 3. IK if cleared before the SAVE to 
tape. Restore the 16K RAM by power- 
down and then LOAD the program. 
CLEAR and then SAVE it back to tape 
again in 16K. Reset RAMTOP to 19710 
and try to LOAD it back. If you suc- 
ceed, you may now SAVE it to tape in 
3K RAM, but it will require 16K when 
it is LOADed back if you want to RUN 
it. 

To keep track of the reduced number 
of bytes remaining during the listing of a 



SUB COMMANDER %^ 

The torpedo tubes are loaded. 
In front of Lhem is an enemy 
aircraft carrier. You order 
"FIRE 2" and "DIVE". Safe below 
the surface you wait. Finally 
the torpedoes hit. But did they 
sink the carrier? No time to 
look, sonar reports a destroyer 
about to make a depth-charge run. 
Everyone on your ship awaits your 
next command. 

Can you survive to become an 
admiral in the Bronze Star Navy? 
You give all the commands. The 
fate of your ship and crew is 
entirely in your hands and mind. 



16K 



$15.00 



FOOTBALL PREDICTOR II 

Know who will win any pro game 
before it is placed. Tne program 
uses statistics you update weekly 
in order to predict the potential 
of each team and the expected 
final score. (includes USFL) 



16K 



$10.00 



ZT 

Can you help little ZT find his 
way home? This hidden maze game 
has four levels of play and is 
different each time it is played. 
A game for the whole family to 
play and enjoy. 



16K 



$ 7.00 



All software designed for the 
T/S 1000 and ZX8l 

Prices include postage and 

handling charges 

Dealer inquiries invited 



BRONZE STAR SOFTWARE 

P. 0. BOX 265 
Chicago Ridge, IL 
60415 



new program, first set RAMTOP to 
19710 by POKE 16388,254 and EN- 
TER; POKE 16389,76 and ENTER; 
and NEW and ENTER. Then enter 
these lines (with the 16K RAM pack in 
place): 

1 DIM A(16) 

2 FOR N=l TO 16 

3 INPUT A(N) 

4 PRINT A(N);"###"; 

5 POKE 32751 +N,A(N) 

6 NEXT N 

RUN and INPUT the following val- 
ues, reading horizontally: 

42 28 64 205 203 14 
229 193 33 20 237 
66 229 193 201 

After checking the printout, add the 
following lines (changing line 1 to the 
USR command): 

1 PRINT USR 32752;"#BYTES 
REMAINING" 

7 STOP 

8 SAVE "BYTES" 

9 GOTO 2 

SAVE to tape for future use with 
GOTO 8. After the SAVE, the display 



should show the table of INPUTs. Now 
delete all the lines except line 1 and 
RUN. The display should show 3101 
BYTES REMAINING. The routine is 
resident above RAMTOP and will not 
be affected by RUN, CLEAR, NEW, 
SAVE, or LOAD as long as RAMTOP 
is not reset above 32752 or the computer 
is not powered-down. 

RAMTOP must be set to 32752 or 
less before "BYTES" is LOADed back 
from tape, and the machine code values 
will then be automatically POKEd in 
when the LOAD is completed. (They are 
not SAVEd to tape as they exist above 
RAMTOP but are reproduced from the 
variables stored in DIM A(16). Line 1 
will have to be reentered after the 
LOAD of a listing other than "BYTES" 
or may be used as a direct command 
(without a line number) at any time dur- 
ing the listing of a new program as long 
as the "BYTES" routine is resident 
above RAMTOP. 

The actual bytes remaining will vary 
slightly from the number displayed but 
when used for most practical purposes, 
such as noting the effects of byte-saving 
techniques, the routine can be very help- 
ful. RAMTOP must be set to 32752 ad- 
dress by POKE 16388,240 and ENTER, 
POKE 16389,127 and ENTER; NEW 
and ENTER for 16K. V 



Read This First 

Before entering the programs in this 
issue, readers should note the follow- 
ing: 

The ROM and RAM requirements 
for using a given program are shown 
at the top of the first page of the arti- 
cle. Observe these carefully. 

NEWLINE and ENTER are used 
interchangeably. 

A letter after a number shows the 
type: b for binary; d for decimal; h for 
hexadecimal. 

In PRINT statements: 

#: Enter a necessary space. 

A (32): Use the graphic character 
on the A key 32 times. The underline 
means use the graphic on that ke> . 

A: The overline means use the key 
in inverse. 

INPUT : An underlined word found 
on the keyboard should be entered 
from the keyboard, not spelled out. If 
the keyword will not ENTER, hit 
THEN, the keyword you want, back- 
space and delete THEN, continue 
entering the line. This memory saving 
technique may be disregarded if you 
have enough RAM. 



FOR TOTAL 

CONTROL 

of Your Timex Sinclair 



Learning 
Imex 
Sinclair 
BASIC 




The Only Programming Manual You'll Need 

Learning Timex Sinclair BASIC, Dr. David Lien's new, 350-page, 

comprehensive manual for the Timex Sinclair 1000 and Sinclair 

ZX80/ZX81. is the one book that answers all your programming 

questions. 

Learning Timex Sinclair BASIC'S simple, step-by-step instructions 

make it ideal for the classroom. And it's a must for all Timex 

Sinclair owners, especially first-time computer users. Don't miss 

this opportunity to learn from a proven teacher of BASIC how to 

write your own custom software. 

Don't waste time with other confusing, incomplete programming 

guides — order Learning Timex Sinclair BASIC now. Fill out the 

coupon or call our 24-hour order line at 800-854-6505, in California 

call 619-588-0996 (8:00 a.m. - 5:00 p.m.). 

30-Day Money Back Guarantee 

If you're not totally satisfied with this book for any reason, return 

it to Compusoft in salable condition within 30 days for a full refund. 

CompuSoft" Publishing 

535 Broadway, Depl # 070783 

El Cajon. CA 92021 



by David A. Lien 



r 

i 

i 

i 

i 

i 

i 

i 

i 

i 



Please send copies of Learning Timex Sinclair BASIC at 

$14.95 each {Calif, residents add 6%) plus $1.65 shipping and 
handling per book within the U.S. Foreign orders, include $2.50 
surface shipping and handling per honk 

Total Enclosed 



Name . 

Address 

City/State/Zip 
Check 



Visa 



MasterCard 



□ 



Expiration Date 



I 



Signature 



Please allow 4 to 6 weeks 
for delivery. 070783 



July/August 1983 c SYNC 



75 



Hardware Review 



The Votem Lawrence A. Kelly 



Votem. Kit: $39.95; assembled and tested: 
$59.95; plus $3 s&h. Down East Com- 
puters, PO Box 3096, Greenville, NC 

27834. 

The Votem, to play on James J. Carr's 
book Digital Interfacing to an Analog 
World (Tab Books, Summit, PA. 1978), is 
an analog interface to Sinclair's digital 
world. 

Analog/Digital Conversion 

Analog (related to analogous) refers to 
relationships by ratios. The analog device 
relates numbers to a turn on a wheel such 
as our rapidly disappearing analog wrist- 
watch; iv me movement of a rod or shaft 
such as the slide rule; or to continuously 
changing voltages or currents such as in 
an electronic analog computer. 

The electronic digital computer, of 
course, also works on voltages but in 
discrete packages or digits as in the digital 
wrist-watch with the liquid crystalline dis- 
play. Digital computers, unlike the watch- 
es, do not count in decimal (0-9) in their 
digits, but rather use a bistable digit which 
is voltage or no voltage, in other words, 
on or off, 1 or 0, true or false. 

What Carr is driving at in the title of 
his book is that most of the devices we 
use to measure and control things are 
analog in nature. Transducers convert 
physical energy such as strain, thermal 
energy, or light energy into electrical 
energy in a continuously changing voltage 
or current related to the amount of ener- 
gy, yes, its analog. In order to control 
things, voltages or currents have to be 
output. 

The Votem is a device which can 
measure external events relating Analog/ 



Lawrence A. Keliy, Ph.D., 28 Countrywood Dr.. 

Morris Plains. N.I 07950. 



Expand the cognitive 
horizons of your 
TS1000tothe 
real world. 



Digital (A/D), but it does not go the other 
way for control, Digital/Analog (D/A). 

A/D by the Votem 

How does the Votem manage the mar- 
riage between the analog and digital 
worlds? It takes advantage of tne tact 
that the Z80 processor uses a crystal to 
generate a pulse at a given frequency. 
This produces a clock to take care of the 
timing of events in the operating cycle of 
the machine. 

The heart of the Votem is a voltage to 
frequency converter (V/F, AD537JH). 
The V/F relates the frequency of the 
Sinclair clock to voltage applied to the 
external connection of the Votem. This is 
done via a machine language program 
(provided in the manual) which converts 
the clock pulses to a count/volt. Basic 
programs can then convert the voltage to 
something meaningful such as the temper- 
ature at the end of the probe and display 
it periodically on the TV screen. 

Temperature Measurement 

The Votem comes with a temperature 
probe of the resistance type with the 
change in resistance proportional to temp- 
erature. By calibrating this probe to C 
(ice) and 100 C (boiling water) one can 
display on the screen the room tempera- 
ture using a Basic program. The calibra- 
tion is all important in the final accuracy 
of the result because the software uses 
these calibration factors in the calcu- 



lations. Since clock frequencies can vary 
from computer to computer, accuracy is 
to a certain extent in the hands of the 
user. 

The Votem can interface with position- 
al devices (e.g., joysticks), photocells (e.g., 
spectrophotometers), and virtually any- 
thing with an output voltage in the 0-1V 
range (e.g., ionization detectors). 

Tape Load Circuit (Earphone) 

The Votem connects via the tape ear- 
phone port and thereby leaves the expan- 
sion port of the computer free. A RAM 
pack or Byte-Back \ RBI control module, 
or both can still be used. The BB1 device 
can be programmed to turn on relays 
which can switch on 110VAC items such 
as lights or coffee makers. The ZX/TS 
owner has an opportunity to do some 
practical things not previously possible. 

Getting the most mileage possible out 
of the device, the frugal designer also 
employed unused portions of the circuitry 
to condition the tape signal to improve 
LOADing, providing audio output of the 
signal and an LED which glows during 
the LOAD. We found this feature to be 
quite useful. Those with LOADing prob- 
lems might find the the Votem a useful 
addition for this reason only. 

With just three integrated circuits- 
only one of which is in a DIP, it is a 
relatively easy kit to assemble, for those 
who like to become intimately involved. 

For those who want to make the most 
out of a Votem/Sinclair combination 
Carr s book is recommended reading. 

The Votem is probably not for those 
who cannot quite remember who Ohm 
was, or which parameter goes on top and 
bottom in his equation. But for those who 
do and would like to expand the cognitive 
horizons of their computers the Votem is 
a must. S 



76 



July/August 1983 c SYNC 



Timex Developments Paul Grosjean 



The printer is out. Three new machines 
are about to hit the market. Another price 
reduction is made. These are among the 
recent developments in the Timex Sinclair 
computer field. 

Timex Sinclair 1000 for $49.95 

In our last issue we reported that Timex 
Computer Corporation had reduced the 
suggested retail price for the TS1000 to 
$69.95. On April 28, 1983, Timex an- 
nounced a further reduction to $49.95. 
Remember the breakthrough of the origi- 
nal ZX80 for $199.95? 

Timex Sinclair 1500 for $79.95 

On May 17 Timex announced the intro- 
duction of the Timex Sinclair 1500, an 
enhanced version of the TS1000. Shipment 
is expected to begin in July. 

The most obvious enhancement is a new 
styled case supporting a full movement 
keyboard instead of the familiar mem- 
brane keyboard. The 40 keys have the 
same layout, commands, functions, graph- 
ics, and characters as the TS1000. The 
second major enhancement is that the on- 
board RAM has been increased to 16K 




Photo I The Timex Sinclair 1500. 




Photo 2. The Timex Sine Ian 



July/August 1983 c SYNC 



and can be expanded to32K by the TS1016 
16K RAM pack. 

The TS1500 is compatible with all 
TS1000 peripherals and software. Stand- 
ard cassette recorders are used for saving 
and loading, but the new instant-load soft- 
ware cartridges being developed by Timex 
will plug directly into the computer. These 
palm-sized cartridges are expected to cost 
from $12.95 to $29.95 and to be available 
in August. 

Timex Sinclair 2000 Series 

Timex also announced on May 17 that 
two computers in the 2000 series would be 
available to retailers in August. One with 
72K RAM is priced at $199.95; the other 
with 40K RAM at $149.95. The video 
display can be output to most color and 
black-and-white TV sets as well as to a 
monitor. 

The keyboard has 40 moveable keys 
arranged in typewriter format with upper 
and lower case letters, repeat key option 
for all keys, 16 built-in graphics characters, 
and 21 user-programmable graphics char- 
acters. Each key performs up to six 
functions. Most of the functions, com- 
ContmueJ on page W, 

77 



Hardware Review 

Memopak High Resolution Graphics Module 

John Herriott 



Memopak HRG Module. $99.95 plus 
$4.95 s&h. From Memotech Corp., 7550 
W. Yale Ave., Denver, CO 80227. 

The Memopak High Resolution Graph- 
ics Module, in dull black matching the 
computer, fits in between the Memopak 
parallel printer interface and the 64K 
memory module. Velcro tape or double 
sided adhesive tape comes with each unit 
to ensure a wobble-free set-up. 

The 18 page instruction booklet, which 
serves only to whet the appetite, begins 
with a brief but lucid account of a "video 



John Herriott, 143 LeMarchant Rd.. 
Nf Id, Canada AIC 2H3. 



St. John's. 



page/' how to set the switches and remove 
the small jumper switch for full use of the 
64K. 



A short program illustrates setting para- 
meter V and calling a routine contained 
in the 2K EPROM. The result is a black 




Instrumentation & Control 

ANALOG INTERFACE BOARD 

8 channels A/D + 8 channels D/A 1.6uS A/D convert time Uses 
BASIC or machine code. Does NOT need Buffered Buss Includes 
pans for piggyback to ZX/TS & RAM. Many jumper and 
switch selectable options Has features which allow 
easy interfacing to other micros. Tested on ZX/TS. 
Apple, TRS-80. CBM 64, others Manual w/software. 
You must see spec sheets to appreciate this board 

$195. 

BUFFERED BUSS- 
DEVELOPMENT BOARD: kit $65. -EF5k 
bare board $ o 5. with connector and manual. 

APPLICATIONS BOOK FOR 'BUSS': Plans& programs for8255 porta EPROM PGR. 40pgs $10. 



SENSIBLE APPLICATIONS 
FOR YOUR SINCLAIR 




**-l 






42 









•»- 



CONNECTORS 




CURE CRASH 
PROBLEMS ! 

Gold plated ribbon cable 
connectors to fit ZX/TS & 
peripherals 

(-ASSEMBLY w/8 cable $18. 

You can add more 
connectors to the assembly 
or create your own 
from parts: 

Female connector 

to ZX/TS ■ ... $7. 

Male connector to 

peripheral" 1 $7. 



UHF 



MODULATOR 




SEE ARTICLE IN 
JAN SYNC • 

• REMOVES INTERFERENCE 
FROM YOUR TV DISPLAY ! 

This modulator is soldered on the com- 
puter's circuit board in place of the 
VHF modulator Requires soldering 
skills. We install for S10 extra plus our 
$3 shipping charge. Satisfaction guar- 
anteed or we will refund you on return 
of a working modulator. 



FREE CATALOG Explaining our products and applications Write 

or call 

TERMS: Please add $3 for shipping and handlinq California r» 
please add R' ?% tax. To order, send check or money order or 



fomputer M ontinuum 

V SOlTsthAve CO^ 

San Francisco, CA 94118 (415) 752 6294 



78 



July/August 1983 c SYNC 



screen with white-lettered MEMOTECH. 
The small black button on the right side 
returns the computer to Basic. 

Armed with this experience, one can 
follow the explanation of how the HRG 
works, the nature of a pixel, a "video 
page," and the bit and byte summaries. 

Thirty subroutines can be called from 
address 8192. There are five varieties of 
routines: Page: manipulation and prep- 
aration of displays. Block: rolling and 
scrolling the display in four directions. 
Character: sketching, unsketching, 
inverse-sketching of user-defined char- 
acters. SINCH: plots ZX81-defined char- 
acters. Line routines draw and wipe out 
lines and fill in areas of your masterpieces. 
PLOT and UNPLOT function as on the 
ZX81 except that the result is a tiny spot 
instead of a big, square blob. 47616 of 
these spots or pixels are possible; 192 
vertical and 248 horizontal. 

SKETCH allows you to design your 
own characters by setting each bit: 

LETC$="10101: ,, 
gives you a line. The * can be used instead 
of for the sake of clarity. By astute use 
of the NESW direction commands one 
can produce a neat cross, thus: 
LET C$= ik l***lNEl*lNElNWl*lNWl* 



My efforts to produce a Russian character 
set (well, one letter actually) developed 
an interesting array of Devenagri and 
Coptic symbols at first! 



5 


REM "L/BOX" 


lis 


LET Y=20 


10 


LET V=40000 


120 


GOSUB 9990 


20 


LETZ$= M STARCH" 


122 


REM MID/HORIZ 


30 


RAND USR 8192 


125 


LET X=60+I 


35 


LET Z$="PL0T" 


130 


LET Y=45 


40 


FOR 1*1 TO 50 


135 


GOSUB 9990 


50 


LET X =10 


137 


REM HI/HORIZ 


55 


LETY=20+I 


140 


LET X=60+I 


58 


REM VERTTCAL/L 


145 


LET Y=95 


60 


GOSUB 9990 


150 


GOSUB 9990 


63 


REM LOW/DIAG 


153 


REM DIAG/R 


65 


LET X=10+I 


160 


LET X=60+I 


70 


LET Y=20+I/2 


165 


LET Y=20+I/2 


75 


GOSUB 9990 


170 


GOSUB 9990 


77 


REM HI/DIAG 


175 


LET X=110 


80 


LET X=10+I 


180 


LET Y=45+I 


85 


LET' Y=70 + I/2 


185 


GOSUB 9990 


90 


GOSUB 9990 


220 


LET X=60+I 


92 


REM MID/VERT 


225 


LET Y=45+I 


95 


LET X=60 


230 


GOSUB 9990 


100 


LET Y=45+X 


500 


NEXT I 


105 


GOSUB 9990 






108 


REM LOW/HORIZ 


9990 


RAND USR 8192 


110 


LET X=10+I 


9995 


RETURN 



Line notes: 

20: Macro page command: combines 
Start, Clear, HRG. 

60: The call is assigned to a subroutine. 



Listing 1 uses PLOT to produce a rep- 
resentation of a portion of a box with 
each line being drawn simultaneously. 
Although the program might appear un- 
wieldy because of the GOSUBS, one can 
watch each of the lines add its bit in the 
proper order. Adding line 37 FAST 
reduces the time the program takes from 
65 seconds to 13, but the joy of watching 
the process is lost! Any use of FAST 
mode should be countermanded with a 
SLOW. The instructions say that one can 
break into a program in FAST mode by 
entering SLOW and then pressing the 
Basic RETURN button. However, I have 
had no success with this, and so I take the 
obvious precaution. 

"LAUNCH", one of the line routines, 
fires black lines up the screen. A neat 
routine to change the firing position holds 
all kinds of game possibilities. 

"Draw If by Robert Boynton (SYNC 
2:4) or "Draw and Store" by James J. 
Hollandsworth (SYNC 2:6) can be suit- 
ably modifed to produce a fairly fine-line 
sketch-pad. 

With the ability to pack pages of graph- 
ics into a Basic string which can be 
SAVEd and unpacked later for display, 
the Memopak HRG is a useful addition 
to a ZX/TS set up. 5 



SPECTRUM 

IS COMING SOON 

oINuLAIR S much heralded colour computer in 
16K and 48K versions with sound, professional key- 
board and high speed load will be known as the Timex 
Sinclair 2000 in North America. 

• Our prices are as follows 

16K $144.95 48K $195 *> 

INCLUDING DELIVERY by inturvd parcel post. NY ntldent* add 
7% utoi tojr. Canadian* add 25% (US tundt) (orcuttomt cfMnnct, 
F.S.T. and delivery by raglalarad mall. 

Delivery is expected in late July and supplies will be 
tight. We are asking for a deposit of $25 to secure your 
position at the front of the waiting list. You will be 
notified to send the balance of your payment when we 
receive stock. 

Order now to avoid a long delay in getting in on the 
hottest computer bargain since the ZX-81 

We also offer, at the lowest prices in the country, all 
Timex Sinclair hardware and software 

ZX printer $89 ^ 

16K Memory Module $45 .*» 

Stabilizer Pad (a must) $6. 9 * 

Postage Extra. 

Please send cheque, money order or VISA number 
and expiry date to 

STREAM COMPUTERS P.O. Box 784 Lewiston, 
NY. 14092 K«y 416-960-2488 



KNOCK DOWN 

LEARNING BARRIERS 



Enter the World of MACHINE LANGUAGE 
With Greater Ease 

Learn How Your Sinclair Works 

with MEMORY SCOPE 

An innovative development in memory control has brought forth 
MEMORY SCOPE, a new program that makes understanding your 
computer and learning machine language much easier. 

MEMORY SCOPE is actually two programs In one. One is a full- 
screen machine programming editor with unique features that make 
entering, revising, and running machine code programs a simpler 
task. The other is an exploratory scope that gives a "live" view of any 
section of memory through a full-screen window that can be rapidly 
scrolled or positioned. 

MEMORY SCOPE can be installed with other programs (space per- 
mitting) to learn more about them or make revisions. 

An ideal learning environment for venturesome beginners or an 
indispensable program development tool for experts. 

Never before has a program provided so much potential for 
discovery, with so many powerful programming features, at such a 
modest price. 

Complete instructions included with many instructional ex- 
amples to get you started. 

Written in Machine Code 
ForTS1000/ZX81 with 16K 

On Cassette for $7.95 add $1.50 for shipping 

BONNIE & CLYDE SOFTWARE 

P.O. Box 13651 
Albany, N.Y. 12212 



July/August 1983 c SYNC 



79 



Timex Developments, continued... 

mands, characters of the TS1000 are re- 
tained and in the same places, but a few 
have been moved, e.g., the number keys 
have the same character placement as the 
standard typewriter keyboards. New func- 
tions have been added to handle the 
increased capabilities of the computer. 
The Basic has also been expanded, most 
notably with READ, DATA, and 
RESTORE. 

Probably the chief difference from the 
1000 that users have been anticipating is 



the high resolution color capability. The 
features include eight colors; control of 
the foreground, background, and border 
areas; a flash command; and a brightness 
control. The display area consists of 24 
lines with up to 64 characters each. The 
high resolution display has 256 dots hori- 
zontally and 192 vertically which can be 
individually addressed. 

A fully programmable sound capability 
is provided by a built-in speaker with a 
range of 10 octaves and 130 semitones. 



The BEEP command allows setting the 
pitch and duration of sounds. Users who 
want to compose music will be able to do 
so on the computer. 

Although the 2000 series continues to 
use cassette saving and loading, an exten- 
sive software line will also be available on 
the new mini-cartridges that plug directly 
into the computer. Another feature is a 
built-in real time clock. This will allow the 
user to run real time programs and coordi- 
nate with appliances. % 



Directory of Suppliers 



Ed. — This Directory supplements the list in our Buyers 
Guide Issue. A few suppliers are repeated because of 
the products carried over or new product listings. 



Aardvark 

2352 S. Commerce 

Walled Lake, Ml 48088 

Acts Audio, inc. 
70 W. Illiana Ave, 
Orlando, FL 32806 
(305)423-0338 

Air Capitol Software 
POBox 12051 
Wichita, KS 67277 

American Micro Products, Inc. 
705 N. Bowser. Suite 1?1 
Richardson, TX 75081 
(214)238-1815 

A. -»- Associates 

175 5th Ave. Suite 31 19 

New York, NY 10010 

Applied Software Development 

Association, Inc. 
Rt. 1 , Box 330 
Parkin, AR 72373-0330 

Asia Tsusho Co., Ltd. 
7-6, 1-chome 
Soto-Kanda, Chiyoda-ku 
Tokyo, Japan 

A, T&A Comp-U-Ware 
2712 G St. 
Middletown, OH 45042 

Audio Vision 

1279 N. Normandie 

Los Angeles, CA 90027 

Biocal Software 
340 Cypress Drive 
Fairfax, CA 94930 

Note: Minimum order: $10. 
Cassettes: $5; listings: 6/$ 10. All 
programs 16K RAM unless 
noted otherwise 



Bom is Prendin Software 
PO Box 28550 
Washington, DC 20005 
Note: SASE with orders. 

Charles J. Bonner 
POBox 91 79 
Norfolk, VA 23505 

Bonnie & Clyde Software 
POBox 13651 
Albany. NY 12212 

Bronze Star Software 

p O Box 265 

Chicago Rdg, IL 60415 

Bug-Byte Software 
100 The Albany 
Old Hall Street 
Liverpool 
U.K. L3 9EP 

Business Management 

Specialists 
PO Box 4073 
Dearborn, MI 48126 

Robert Cannon 
309 N. Broadway 
Yonkers. NY 10701 

Circle Chess Journal 

Box 63 

Des Plaines, IL 60017 

Cobra Technology, Ltd. 
378 Caledonian Rd. 
Islington 

London, U.K. N1 1DY 

John Richard Coffey 
PO Box 448 
Scottsburg, IN 47170 



Compu-Pak 

2615 Waugh Dr., Suite 295 
Houston, TX 77006 
(713)523-3691 

Computer Add Ons 
7-9 Thane Works 
Thane Villas 
London, U.K. N7 

Computer Assistance Inc. 
PO Box 3402 
Cincinnati, OH 45201 
(513)381-8778 

Computer Practice 

Keyboard Co. 
616 9th St. 
Union City, NJ 07087 

Computer Software Associates 
50 Teed Drive 
Randolph, MA 02368 

The Computer Trader 

PO Box 20976 

San Diego, CA 921 20 

Computronics 
Box 117 
Okemos, Ml 48864 

Compuwiz Software 
PO Box 390078 
Mountain View, CA 940o9 
{415)961-7204 

CRC Software 
2901 Auburn Rd. 
Auburn Hgts, Ml 48057 
(313)852-3711 

C-20 Magazine 

PO Box 3801 

Wichita. KS 67201-3801 



Curry Computer 
5344 W. Banff Ln 
Glendale, AZ 85306 

Datametrics 

Trout Rd., West Drayton 
Middlesex, U.K. 
Ph: West Drayton 43168 

Daydesign 

790 E. Big Beaver Rd. 

Troy, Ml 48084 

Discount Software 
320 E. 59th St. 
New York, NY 10022 
(212)486-0980 

A. Doty 
POBox 11023 

Ferguson, MO 63135 

Dynamic Designs 
PO Box 872 
Norco,CA91760 

Edson Electronics 
POBox 151211 
Tampa, FL 33684 

Electronic Specialists, Inc. 
171 S. Main St. 
Natick, MA 01 760 

Emvee Software 
10 Mythrop Rd. 
Lytham, Lancashire 
U.K. FY8 4JD 

Ener-Z Co. 
PO Box 635 

Ft. Washington, PA 19034 

Ezra Group II 
PO Box 5222 
San Diego, CA 92105 



80 



July/August 1983 c SYNC 



Felix Software (Dept SC1 ) 
19 Leighton Ave. 
Pinner, U.K. HAS 3BW 

Bob Fingerle 

39639 Embarcadero Terr. 

Fremont, CA 94538 

Fisher-Marriott Software 
9c Abbey Hill 
Kenilworth 
Warwickshire, U.K. CV8 1LW 

(0926)511254 

Florida Creations 
POBox 16422 
Jacksonville, FL 32245 

The Forth Dimension 
1451 N. Union St. 
Middletown, PA 17057 
(717)944-6000 

The Fourth Design 

PO Box 1 406 

Niagara Falls, NY 14302 

Frog Software 
PO Box 95 
Glenmont, NY 12077 

GCM Electronics 
POBox 6152 
Ft. Smith, AR 72906 
(501)646-2100 

General Systems Consulting 
2312 Rolling Rock Dr. 
Conley, GA 30027 

N. J. Gipson 

43 Penn Dr., RD 6 

Coatsville, PA 19320 

Gladstone Electronics 
1585 Kenmore Ave. 
Buffalo, NY 14217 

Rois R. Harder 
995 Shakespeare Ave. 
North Vancouver, B.C. 
Canada V7K1E7 

L Harmon 

4909 Clearlake Dr. 

Metairie, LA 70002 

Hawg Wild Software 

PO Box 7668 

Little Rock, AR 72217 

Haymarket Software 
PO Box 14026 
Jacksonville. FL 32238 

Hewson Consultants 
60A St. Mary's St. 
Wallingford, Oxon 

U.K. OX10 0EL 

Home Applications 
2169 Hikido Dr. 
San Jose, CA 95131 

Intercomputer, Inc. 

PO Box 90. Prudential Center 

Boston, MA 02199 

July/August 1983 L SYNC 



J K Audio 

PO Box 3295 

Escondido, CA 92025-0580 

Kamel Technology 

2802 W. Bay Area Blvd., #2106 

Webster, TX 77598 

Kabre Electronics 

17880 Los Alamos 
Fountain Valley, CA 92708 
(714)963-3118 

Ksoft 

845WellnerRd. 
Naperville, IL 60540 

Laminar Inc. 

1514 Fairview, Box 12332 (S) 

Columbus, OH 43212 

Larsoft Software 
PO Box 255 
Waterloo, IL 62298 

Laserscan Electronics 

Corporation 
2305 Broadway 
Riviera Beach, FL 33404 

(305)842-4255 

Markel Software 

PO Box 2392 

Secaucus, NJ 07094-0992 

M. H. Marks Enterprises 
315 ThornberryCt. 
Pittsburgh, PA 15237 
(412)486-1694 

Martech Games 
9 Dillingburgh Rd. 
Eastbourne 
East Sussex, U.K. 

MAV Microproducts 
POBox 31256 
Seattle, WA 98103 

Memory Master 
PO Box 774 
Barnegat, NJ 08005 

Memotech Corporation 
7550 W.Yale Ave. 
Denver, CO 80227 

(303)986-1516 

Note: See Memoteehs ads in 
this issue for price update. 



Microcomputers Plus, 
349 E. Main St. 
Galesburg, IL 61401 
(309)342-9572 

Micro Developments 
Box 1140 
2000 Center St. 
Berkeley, CA 94704 

Micrografix 
306 Double Tree 
Lewisville, TX 75067 

MicroSync Software 
7440 N. Rockwell 
Chicago. I L 60645 



nc. 



Computes mean, variance and standard 



Computes regression coefficients 



SIMPLEX SOFTWARE 

INTRODUCES A NEW LINE OF QUALITY, AFFORDABLE 

AND RELIABLE 16K CASSETTE SOFTWARE FOR 

2X81 and TIMEX/ SINCLAIR 1000. 



Introductory Prices Good Until 8/31/83 
RECREATIONAL-PAC: %JA?& .... $9.95 

1 . BIORHYTHMS - Computes and plots 4 weeks of your bio- 
rhythms 

2. ANIMALS - Popular artifical intelligence learning game 
ART-PAC: $J>&S ....$9.95 

1 COMP-U-SKETCH - Computerized version of popular 
ETCH-A-SKETCH toy 

2. MICRO ORGAN - 4 octave organ music through your TV 

3. KALEIDOSCREEN - TV screen becomes a computerized ka- 
leidoscope 

EDU-PAC: ...$9««£ ....$7.95 

1 MATH DRILLS - 4 programs with 4 to 5 levels and score- 
board 
2. COMPUTER AIDED INSTRUCTION - General purpose educa- 
tional program 
MATHSTAT-PAC: .... %}SX&5 .... $8.95 

1. STATISTICS 
deviation 

2. LINEAR REGRESSION 
and displays equation 

3. VECTOR MATH - Adds two vectors and provides resultant 
vector 

4. SIMULTANEOUS EQUATION SOLVER - Solves system of 

simultaneous equations 
FINANCE-PAC: ^Sf€ ....$7.95 

1. CHECKBOOK BALANCER - Reconciles check register with 
bank statement 

2. NET PRESENT VALUES - Computes net present value of a 
series of cash flows 

3. AUTO LOAN ANALYSIS - Computes amount of loan and 
monthly payments 

HOME-PAC: $£9^ ..$19.95 

20 PROGRAMS - Best software value in America. > 
grams in the above packages plus: 

1. STAR INVADER - Mini space invader game with 1 invader 

2. MACHINE LANGUAGE MONITOR - Utility program enters and 
list hex code 

3. RENUMBER - Utility program renumbers BASIC programs 

4. 21 Page User's Manual (Manual alone $2.95 - credited to 
future purchase of HOME-PAC) 

COMBO:.. ...$as05 ....$6.95 

Computerized variation of popular BOGGLEnidden word game 
program, with 4x5 game board (2 to 8 players) 

GUARANTEED 

All programs are supplied on quality cassette tapes which are 
guaranteed to load and run (defective software will be 
replaced if returned within 30 days) 
ACT NOW! CLIP and MAIL the COUPON BELOW! 

Mail to: SIMPLEX SOFTWARE, DEPT. A4, 

P.O. Box 792, New Brunswick, N.J. 08903 



America. All the pro- 



□ Please send me 
Please rush my 
order 


more informs 

PRICE 
UNTIL 8/31 


tion. D Deal 

PRICE 
AFTER 8/31 


er infor 
QTY. 


mation 
TOTAL 


RECREATIONAL- 
PAC 


$ 9.95 


$11.95 






ART-PAC 


9.95 


11.95 






EDU-PAC 


7.95 


9.95 






MATHSTAT-PAC 


8.95 


10.95 






FINANCE-PAC 


7.95 


9.95 






HOME-PAC 


19.95 


29.95 






HOME-PAC 
MANUAL 


295 


2.95 






COMBO 


6.95 


8.95 






Shipping & Handling - (Foreign orders $3.00) 


1.50 


New Jersey Res. Add 6% Tax 




Total 




D Check D Money Order D VISA 
□ Mastercard 





Account No. 
Name 



_Exp. 



Address 
City 



State 



.Zip. 



IOK ZX-81 I Mimmm OMI'I TERS K>K RAM Kiqd 

POLYMATH IS HERE TO HELP YOU! 

Now you can transform your Timex/Sinciair computer into a 
powerful teaching aid Polymath will help you solve and check 
\our math problems, fast and efficiently 

Let Polymath be your computer tutor! 

• Solve Quadratic Equations 

• Solve Cubic Equations 

• Factor Numbers 

• Find Prime Factors 

• Find GCD 's 

• Evaluate Polynomials 

• Evaluate for X and Y 

• Plus much much more' 

Solve equations quickly and accurately Polymath is an entry 
into the wider fields of science and technology It will guide 
you towards algebraic logic, the key to taster, efficient 
programming 




menu -driven 

user friendly 

Written 

In 

Basic/ MC 

For 

Fast, 

Crash-proof 

Results. 

Polymath comes on quality cassette with documentation 

To Order: 

Send check or money order for S 19/' s ppd. To: 
POLYMATH, P.O. Box 800, Felton, CA 95018 

Calif lea Please add i\ v„ tax 

orders Outside Continental ISA add $ I ,MI 



ORDER NOW 
Only $19." ppd. 

POLYMATH 

For 

Inquiring 
Minds 

Of 
All Ages 



(RamTray $ 14 95 




Accommodates NEW 2040 Printer. 
Our custom molded tray securely holds your 
T/S 1000, T/S 16K RAM pak and cassette drive. 
Control panel provides for optional switches, All 
connecting cables are enclosed. For immediate 
shipment send $14.95 plus $2.00 UPS. ($5.00 
foreign) U.S. currency, check, money order, 
credit card (type, number, expiration date). 
Sorry, no C.O.D. 



Free with every tray, Sinclair drivenPROM Burner sche- 
matic, operating system software, and burn machine code. 
You can burn and execute 2716, 2732, and 2732A. Copy 
and duplicate software included. Boards, kits available. 
For immediate shipment send ALL the money you have! 
(or wait for our info pak) 



Dealer and distributor inquiries invited. 
RAM products made in U.S.A. 
TOm 4736 N. Milwaukee Ave. - Chicago, IL 60630 U.S.A 



Robert J. Midura 

19 Merrifield St., Apt 3F 

Worchester, MA 01605 

Mindware, Inc. 
15 Tech Circle 
Natick, MA 01760 
(617)655-3388 
Note: Order all products 
from: 
Eagle Sales 
15 Tech Circle 
Natick, MA 01760 

Robert C. Moler 
5999 Secor Rd. 
Traverse City, Ml 49684 

MT-Soft 
Box 2638 
Aurora, IL 60507 

Mule Electronics 
Dept. 31 0A 
444 Lincoln Bl, 
Venice, CA 90291 

New World Concepts, Dept. C 
PO Box 587 
Ogden, UT 84402 
1-801-393-4819 

Orbyte Software 

POBox 

Waterbury, CT 06720 

(203) 753-8308 

Note: Prices include s&h 3 or 
more programs: 10 percent off. 

Original Programs 
3763 W. Crocus Dr. 
Phoenix, AZ 85023 

P.A.L. 

PO Box 24362 

Ft. Worth, TX 761 12-9362 

Panda Software 
51 Elgin St. 
Shelton 
Stoke-on-Trent 
U.K. ST4 2RD 

Pegasus Micro Systems 
PO Box 397 

Chestertown, MD 21620 
(301)348-5865 

People's Computer Supply 
PO Box 664 
Sidney, NE 69162 

Note: Products from. Memo- 
tech, William Stuart Systems, 
Advanced Interface Design, 
Software Expense Cutter, USI 
International Monitors, Bi-Pak, 
Hunter, D. Fristch Electronic 
Designs, Emvee Software, Key- 
board George Risk Industries, 
Haven Hardware, and others. 

Plus + Pac Systems 

International 
POBox 10300 
Chicago, IL 60610 

(312)951-7671 



Powerplay Systems 

PO Box 752 

New York, NY 11377 

Praise Data Systems 
205 Pawnee St. 
Ronkonkoma, NY 1 1 779 

RAm 

4736 N. Milwaukee Ave. 

Chicago, IL 60630 

Ramex International 
PO Box 50 
Utica, Ml 48087 

Rayco 

PO Box 484 

Delaware, OH 43015 

Research Applications 

Products 
4561 Paloma Lane 
Yorba Linda, CA 92686 

John Riggs 
1114 Elaine Ave. 
Livermore, CA 94550 

R-Tek 

7326 Ridgeberry Dr. 

Houston, TX 77095. 

Run-it Software Club 
732 S. Sherman 
Chicago, IL 60605 

(312)427-6526 

G. Russell - Electronics 
RD 1, Box 539 

Centre Hall, PA 16828 

St. Martin's Press 

1 75 5th Ave. 

New York, NY 10010 

Sight and Sound Electronics 

1120 Bailey Hill Rd.#10 
Eugene, OR 97402 
(503)485-6274 

Sikes Software 
PO Box 1 1 5 
Edmeston, NY 13335 

Silicon Valley North, Dept. SBG 
PO Box 2442 
Hammond, IN 46323 

Sinclair Place 
PO Box 2288 
Redmond, WA 98052 

Note: Products from: Thurnal 
Electronics, Down East Com- 
puters, Memotech, dk'Tronics, 
Mindware, Aerco, Haven Hard- 
ware, William Stuart Systems, 
Kopak Creations, Abacus Elec- 
tronics, Audiograph Co., Mel- 
bourne House, Reston Publish- 
ing. 

Sinclair Supply Shack 
22626 Woolsey Dr. 
Novi, Ml 48040 



82 



July/August 1983 c SYNC 










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Sirius Ware 

6 Turning Mill Rd. 

Lexington, MA 021 73 

Skelly Computing 

50 Riverside Dr. - Camelot 

Lake Placid. NY 12946 

SKT Enterprises 
PO Box 23955 
Washington, DC 20024 

Softsync, Inc. 
14 E. 34th St. 
New York, NY 10016 
(212)685-2080 

The Software Farm, Dept. C. 
Craigo Farm, Botany Bay 
Tintern, Gwent, U.K. 

Software Supermarket 
87 Howards Lane 
London, U.K. SW1 5 6NU 

Sophia Systems 
15122 Pheasant Dr. 
Surrey, B.C. 
Canada V3R 4X6 

Sourceware, Inc. 

PO Box 1579, Dept. SI-1 

Vernal, UT 84078 

Space Breaker 
PO Box 8104 

Green Bay, Wl 54308 



Spyder Electronics 
PO Box 4172 
Morgantown, WV 26505. 

Stuart Software 

25381 -G Alicia Parkway, 

Suite 316 

Laguna Hills, CA 92653 

Sussex Software House 
57Bexhill Rd. 
Eastbourne 
E.Sussex, U.K. 

Syber, Inc. 

1325DillerRd. 

Ocean Springs, MS 39564 

SyncWare Co. 
PO Box 5177 
El Monte, CA 91 734 

Synergistic Design 
PO Box 41 1023 
Chicago, IL 60641 

Tape masters 

PO Box 38651 
Dallas, TX 75238 

(800)527-1227 

(214)349-0081 (in Texas) 

Technology Products 

and Services, Inc. 
1012 Clearwater PI. 
POBox 10207 

West Palm Beach, FL 33404- 
1207 



3G Company, Inc. 
Rt. 3, Box 28a 
Gaston, OR 971 19 
(503)662-4492 

Timeworks, Inc. 

405 Lake Cook Rd., Bidg A 

Deerfield, IL 60015 

TS User(Yagsee Publishing) 
POBox 155 
Vicksburg, Ml 49097 

Turner, Elcy&Com. 
PO Box 395 
Port Huron. Ml 

2-Bit Software 
PO Box 2036 
Del Mar, CA 92014 
(619)481-3629 

UAS 
Box 612 

Haddonfield, NJ 08033 

User Friendly Research 
478 W.Hamilton Ave., 
Suite 154 
Campbell, CA 95008 

T. W. Vessels 

Rt 1.Box77-S3 
Brownsville, KY 42210 

Sean Wilson 

20 Lakevista Ave. 

Markham, Ont. Canada L3P 1 H5 



Bob Woish 
102 North Lane, B3 
Conshohocken, PA 19428 
Note: All items sent postpaid . 

J. M. Yocum 
POBox 1955 

Corvallis, OR 97339 

York 10 Computerware 
24573 Kittridge St, Dept. S-4 
Canoga Park, CA 91307 

Youngs' Computer Publications 
2 Woodland Way 
Gosfield, Halstead 
Essex, U.K. C09 1TH 

Zebra Systems, Inc. 
78-06 Jamaica Ave. 
Woodhaven, NY 11421 

Zopf Industries 
121 W. Mt.Hope 
Lansing, Ml 48910 

Zor Khan 
Box 31569 
Aurora, CO 80041 

Z-West 
POBox 2411 

Vista, CA 92083 
(619)757-1387 

ZXSystems Software 

PO Box 8264 

Pembroke Pines, FL 33024 V 



64k INSIDE!!! 




No wobbles! 
No bulty add-ons! 
No fear of crashing if bumped! 

The 64KTis64kof user transparent memory 
which mounts INSIDE the TS 1000 . 

It Installs In a minute with NO soldering . 
Easy to follow instructions. To order the 64 KT, 
send $1 15.00 (plus $4.00 shipping & handling ) 
check or money order to: 

INDEPENDENCE RESEARCH 
P.O.BOX 1497 
OREM, UTAH 84057 

If you have a ZX81 , or a TSIOOO with a serial * prefix 
of T or D, specify the 64KZ 




SPYDER 



ELECTRONICS 



presents the 

SPYDER CHARACTER BOARD 



. Play and create high resolution games 

. Create your own character sets 

. Includes 2K of memory 

. Use easy to read reverse video 

. Compatible with RAM Packs and ZX Printer 

. Installs easily (complete instructions included) 

Included with the Spyder Character Board: 

- Full documentation to get the most from your ZX81 

- Demo tape with character sets 

- Zap-Em high resolution game 

- Spyder Software Catalog 



Bare Board -$14.50 
Kit -$24.50 

Assembled -$29.50 

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84 



July/August 1983 E SYNC 



Just Far Fun 



8k ROM: 2k UK) RAM 



Generally SYNC prefers articles in some depth to help you get more out of your 
computer. However, we receive many short programs that illustrate a point, 
demonstrate a technique, or show something the reader has found interesting. 
"Just for Fun" shares these programs with you. If you learn something, great. If 
you have some fun, great. If you have some that you want to share, send them 
to: Just for Fun, SYNC, 39 E. Hanover Ave., Morris Plains, NJ 07950. 



Horizontal Bar Graph 

Michael W. Schultz 

Type in the program. Then with your 
computer in either FAST or SLOW mode, 
hit RUN and ENTER. As the prompts 
appear, enter the starting year of your 
graph, the number of bars you wish to 
compare, and the interval between years 
(e.g., 1, 5, 10). When the words 
"HORIZONTAL BAR GRAPH" appear 
on the screen, begin entering the data, 
one number at a time. Each value must 
be below 51 so scale your data accord- 
Michael W. Schultz, 3650 Mossvale Dr. 20-D, 
Mobile. AL 36608. 



ingly if you are INPUTting larger num- 
bers. The first year entered will be shown 



10 REM "HORIZONTAL BRR GRflPH" 

20 PRINT "ENTER YERR TO 5TRRT 

30 INPUT D 

4.0 PRINT 

■50 PRINT "ENTER NUMBER OF BRR = 

DE5IRED" 

S0 INPUT N 

r-0 PRINT 

30 PRINT 
:N YERRS" 

30 INPUT R 

.10 SCROLL 

120 PRINT TRB S 
3RPH" 

-30 FOR 1=1 TO N 

40 SCROLL 

150 INPUT Z 

^60 PRINT D 

170 FOR X=S TO ZfS 

150 PLOT X.. 

90 NEXT X 

rOO PRINT Z 

210 LET D=D*-H 

w20 NEXT t 



ENTER INTER URL BET UE 



■HORIZONTAL Bfl 



with its bar graph and the exact data 
number. As each following year is shown, 
the display will be SCROLLed up the 
screen; after about twenty bars the display 
will start disappearing off the top of the 
screen. 

This program is designed to be flexible 
in structure so the user can easily edit it 
to meet his individual needs, such as 
personal finances, business applications, 
and so on. This can be done by simply 
changing the prompts in lines 20 and 80. 

Bar graphs, either vertical or horizontal, 
are very useful as visual aids in comparing 
statistical values. Vertical graphs are more 

Continued on page 114. 



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Machine Code and Your TV Screen 



Harry Doakes 



One of the ways that Basic is slow is in 
putting things on the screen. Have you 
ever played a game in Basic and you 
wanted things to zip across the screen, 
but, instead, they crawled? It is frus- 
trating, but Basic is simply very slow in 
this department. In the 8K Basic SLOW 
mode, even something as simple as 

10FOR A = lTO 10 

20 PRINT A 

30 NEXT A 
takes a long time. (Try it and you will 
see.) 

You can speed up the process of put- 
ting something on the screen by using 
machine code, but, to do that, you must 
have some understanding of how the com- 
puter puts things on the TV. This is a 
little technical, but do not panic— it will 
not last long. 

TV Guide 

Somewhere in RAM there is a block of 
memory called the display file. This is 
where the computer stores what will go 
on your TV screen. Depending on how 
long your program is, the display file 
could be almost anywhere in memory. 
For example, when there is no program 
in the computer, the display file starts at 
location 16509— near the bottom of RAM. 
With a 16K RAM pack and a long pro- 
gram, the display file might start way up 
around memory location 32000— almost 
at the top of memory. 

To put something on the TV screen, 
the computer has to know where the 
display file starts. It keeps track of that 
starting point as one of the "system vari- 
ables." The people at Sinclair call this 

Harry Doakes, PO Box 10860, Chicago, IL wmio 
July/August 1983 c SYNC 



particular system variable "D-FILE" (for 
"display file"), and it is at the same place 
for 4K and 8K Basic — memory locations 
16396 and 16397. 

Any time you want to know where the 
display file begins, just look at those two 
memory locations. In Basic, you can do it 
like this: 

PRINT PEEK (16396)+256*PEEK 
(16397) 

Notice that you must multiply what is in 
the second memory location by 256, and 
add it to what is in the first memory 
location. This is similar to the way you 
load a number into a register pair in 
machine code— first comes the remain- 
der, then comes the quotient. 

Short and Sweet 

One other thing you need to know 
about the display file is that it is only as 
long as it needs to be. The display file 
takes up space that otherwise could be 
used by a Basic program or by variables. 
Since some Sinclair computers come with 
only a small amount of RAM, it is import- 
ant to use memory efficiently — and that 
means keeping the display file short. 

In the display file, each line of the TV 
screen shows up as a string of character 
codes (numbers between and 63, or 
between i2n and 191 for reversed char- 
acters—white on a black background). 
The last character code in each line is an 
ENTER code. 1 18. (The complete list of 
character codes is in the appendix to 
your manual titled "The Character 
Set.") 

If a line on the TV screen is empty, 
then the only thing in that line will be the 
ENTER code. This is about as short as 
you can get. 



Taking a Look 

Let's take a look at the display file. 
Type in and run the program in Figure 1. 

Figure 1. 



10 



40 
50 



6C 

70 

PEEK 

SO 

90 



PRINT "HELLO" 

PRINT 

PRINT 

PRINT "OK" 

PRINT 

FOR A=0 TO 12 

LET DFILE»PEEK (16396) +256* 

• 97 ) 
PRINT PEEK (DFILE+A) 
NEXT A 



Your screen should look like this: 



118 

42 
49 
49 

118 
118 
118 




The numbers in the bottom part of the 
screen are the first 13 numbers in the 
display file. If you check them against the 
appendix of your manual, you will find 
that they match up exactly to the first 
dozen characters on the screen, including 
the ENTER code at the end of each line. 

But notice: the first byte in the display 
file is always an ENTER code. 

87 



Quick-change Artist 

When something is added to a line in 
the display, everything in the display file 
has to move— shifting down one position 
to make room. That takes time, and it 
can get pretty complicated. The easiest 
way to get something on the screen is to 
start out with something there, then 
change it. 

For example, try running the Basic pro- 
gram in Figure 2. 

Figure 2. 



10 PRINT "X" 
20 LET DFIl 
30 FOR A=0 TO 63 

40 LET DFILE^PEEK (16396) +256* 
PEEK (16397) 

50 POKE DFILE+1,A 
60 NEXT A 

(Line 20 is necessary only for running the 
program in 4K Basic, in which the value 
of "D-FILE" changes every time you 
create a new variable.) 

If your computer can run in SLOW 
mode, you will see the character in the 
upper left-hand corner of your screen 
change quickly, running through the reg- 
ular character set. 

It runs pretty quickly, but, as you would 
probably guess, it runs much, much faster 
in machine code. How can we translate 
this routine into machine code form? 



The first thing we have to do is rewrite 
the "FOR/NEXT" loop into a simpler 
form. Remember, Z80 machine code has 
nothing exactly like FOR and NEXT. The 
results are shown in Figure 3. 

Now we have solved the problem of the 
loop; we can use load, increment, and 
jump instructions to replace lines 20, 40, 
and 50. 

But we will also need to use two new 
kinds of load instructions— instructions 
that will work the way PEEK and POKE 
work in Basic. 

To do a machine code PEEK at lo- 
cation 16396, use this instruction: 

LDA,( 16396) 
The equivalent in Basic is 

LET A=PEEK (16396) 
However, you can use this instruction 
only to load register A. 

Remember, there is a big difference 
between 

LDA,5 
and 

LDA,(5) 
The first one puts the number 5 in register 
A. The second one puts whatever number 
is in memory location 5 into register A. 
This is the difference between 

LETA=5 
and 

LET A = PEEK (5) 
The number in parentheses is some- 



times called a pointer \ and that is a good 
way to remember how it works. It points 
to where the computer will find the num- 
ber it is going to load. 

As you might expect, the machine code 
version of POKE uses the same kind of 
pointer notation. The instruction 

LD(16396),A 
works like 

POKE 16396, A 
The number in register A goes into mem- 
ory location 16396. 

Again, you can use this instruction only 
to load register A. 

Figure 3. 

10 PRINT "X" 

20 LET DFILE«0 

30 LET A«0 

40 LET DFILE=PEEK ( 16396) +256* 

PEEK (16397) 

50 POKE DFILE+1,A 

LET A-A+i 
70 IF A<64 THEN BOTQ 



Doing the Two-step 

You can also do a machine code PEEK 
or POKE with the register pairs BC, DE, 
and HL. One way is to load each register 
individually. For example, 

LDA,( 16396) 

LDL,A 

LDA,( 16397) 

LDH,A 



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July/August 1983 c SYNC 



would load the system variable "D-FILE" 
into register pair HL. 

But you can do the same thing with a 
single instruction: 

LDHL,( 16396) 
This automatically loads the number at 
location 16396 into register L, and loads 
the number at location 16397 into register 
H. It does two steps at once. This is faster 
for the Z80 processor, and easier for you. 
You can also use this instruction with 
the other two register pairs, BC and DE. 
And you have probably guessed already 
that, if you can PEEK with any register 
pair, you can simply reverse the process 
to do the machine code equivalent of a 
POKE. You are right - 

LD(16396),HL 
is equivalent in Basic to 

POKE 16396,L 

POKE 16397.H 

Pointers by the Pair 

So far, we have covered the ways that 
you can PEEK or POKE to a specific 
numbered location. The number in par- 
entheses in the machine code instruction 
always points to the memory location that 
is involved. 

But in Basic, you can also use PEEK 
and POKE with variables, e.g., commands 
such as 

LETA=PEEK(HL) 
or 

POKE HL,A 
Can you put parentheses around the name 
of a register in machine code, and use it 
as a pointer? 

Yes, but only sometimes. 

A memory location is a number be- 
tween and 65535. That means it will 
take two registers— a register pair— to 
handle the number. As a result, you can- 
not say 

LD A,(B) 
but you can say 
LD A,(BC) 

In addition, register pairs BC and DE 
can be used only to PEEK or POKE with 
register A. Remember, register A is 
special. It is the register you can add to or 
subtract from, and it has many of its own 
special instructions we have not seen yet. 

Here are the only machine code PEEK 
and POKE instructions that use register 
pairs BC and DE: 

LDA,(BC) 
LD A,(DE) 
LD (BChA 
LD (DE),A 
That is not much, certainly. What about 
register pair HL? 

Pay close attention here — this is 
important: 

In almost any instruction in which you 
can use one of the seven regular regis- 
ters—A, B, C, D, E, H, and L— you can 
also use register pair HL as a pointer. 

July/August 1 983 « SYNC 



Here are a few examples: 

LDB,(HL) 

LD (HL),E 

ADD A, (HL) 

CP(HL) 
If you stop to think about it, you will 
realize that is pretty impressive. This 
means you can use almost any memory 
location just like a register, so long as 
register pair HL is pointing to that mem- 
ory location. 

Whew 

By now you are probably ready for a 
rest. But we are so close to being done 
with the machine code version of our 
quick-changing number program, so let's 
finish it up fast. Figure 4 shows the pro- 
gram so far. 

Figure 4. 

10 PRINT "X" 

ET DFILE«0 

I FT A»0 
40 LET DFILE«PEEK a 6396) +256* 
PEFf ( 16397) 

50 POKE DFILE+1,A 

60 LET A=A+1 

70 IF A<64 THEN GOTO 30 



If we use register A for A and register 
pair HL for DFILE, we can translate it 
just about line by line. Starting with line 
30, Figure 5 shows what we have so far. 





I i 


62, 0, 




LD Hi.., ( 16396) 


42, 12,64, 




INC HL 


35, 


LOOP 


LD <HL),A 


119, 




INC A 


60, 




CP 64 


254,64, 




JR C,-6 


56 n - 6, 




RET 


201 




Figure 6. 




10 


LET 0=17390 




20 


FOR A=0 TO 12 




30 


PRINT A; "########":, 




INPUT B 






POKE A+D,K 




60 


PRINT PEEK (A+Q) 


, 


70 


NEXT A 




80 


CL8 




90 


PRINT ' i 




100 


LET B-USR (Q) 






Figure 7. 




10 


PRINT"*' 1 00000000 




1 1 ! (163 


*PEE 


K (16397) 






LET DE-DE+: 






LET HL-DE 




50 


LET A=PEEK (HL) 




60 


L tr T A=A+1 






IF A<38 THEN GOTO 110 


SO 


POKE HI. ,28 




90 


LET HL=HL-1 




100 


GOTO 50 




1 10 


POKE HL,A 




120 


GOTO 30 





Now let's poke this routine in and run it 
using the loader program in Figure 6. 
(Notice that PRINT "X" is part of the 
Basic program.) 

First reserve space at the top of mem- 
ory like this: 
4K ROM: Type 
PRINT USR{620) 
Wait until the screen clears. Then type 
again 

PRINT USR(620) 
8K ROM: Enter this program: 
10 POKE 16388,-20 
20 POKE 16389,PEEK 16389-1 
30 NEW 
The program in Figure 6 is designed 
for a ZX80 or ZX81 with IK of RAM. 
For a 2K TS1000, change line 10 to 

10 LET 0=18414 
If you are using a 16K RAM pack, change 
line 10 to 

10 LET 0=32750 
Now, for either ROM, type in the pro- 
gram in Figure 6. 

Run the program and enter the num- 
bers in the right-hand column of Figure 5 
in exactly the order they appear. 

Now you will see the character change 
even faster than the TV changes the 
screen— you may find it hard to believe 
anything happened at all. That \sfast. 

Doing It Yourself 

You can also use the PEEK function to 
find out what is in a particular location 
on the screen. Figure 7 gives a short 
program that turns your display into a 
counter. 

Can you work out the machine code 
program that will do the same thing? If 
you try running it, watch out — the lowest 
digits will probably flash by so fast, you 
will not be able to see them at all. 

Variables— in Machine Code? 

Now we know how to move a number 
between a memory location and a regis- 
ter. We can move the number from a 
register to a memory location (like the 
POKE command in Basic), or move it 
from the memory location to a register 
(like the PEEK function in Basic). 

Besides looking at and putting things 
on the TV screen, there is something else 
we can use the machine code PEEK and 
POKE for— something even more useful 
and important. With these instructions, 
we can create our own machine code 
program variables— as many of them as 
we like. 

Here is how it works: 

Suppose we designate a specific byte 
of memory as a variable. (The best way is 
to choose a byte of memory that is near 
the machine code program. That way, it 
will be in protected memory, and will not 
be accidentally changed by the Basic sys- 
tem.) We can store a number at that 

89 



With variables, it is easier than ever to translate a program 
from Basic to machine code. 



memory location, and put the number 
into a register only when we need it. 

For example, if we have a variable at 
location 17000, we can add 5 to it with 
these instructions: 

LD A, (17000) 

ADD A,5 

LD(I7000),A 
A one-byte variable can hold any num- 
ber from to 255. To hold a larger num- 
ber, we can use a variable that takes up 
two bytes. It can hold any number from 
to 65535. We could add 5 to that kind of 
variable like this: 

LDHL,( 17000) 

LD DE,5 

ADD HL,DE 

LD (17000), HL 
Think for a moment about what this 
means. Up till now, we have only had a 
few registers to work with. As a result, we 
could keep track of only a few numbers 
at once— one number in each register. 
But by using variables in our machine 
code programs, we can keep track of 
many different numbers. There is really 
no limit to the number of variables we 
can use in a machine code program 



except the amount of available memory. 

However, we must keep in mind that 
using variables takes more instructions 
than keeping all the numbers in registers. 
It also makes your machine code pro- 
grams run a bit slower since it takes time 
to get variables from memory and load 
them into registers, and then to move 
them back from registers into memory 
after you are finished working with them. 

It takes time— but not much time. For 
example, on your computer it takes an 
extra 8 one-million ths of a second to get a 
one-byte variable and then put it back. 

That kind of time, we can usually 
afford. 



LD A, (170O2) 


qet 


R 


LD B,A 






LD A, (17003) 


qet 


S 


ADD A,B 


add 


them 


LD (17001) , A 


put 


result in Q 



There is a big advantage to using 
variables, though, that really makes it 
worthwhile. With variables, it is easier 
than ever to translate a program from 
Basic to machine code. A few more in- 



structions are required than before, but 
with variables you can translate lines of 
Basic more directly. 

Up until now, for example, we have 
had trouble with a line like 

LETQ=R+S 
First we had to break it down to 

LETQ=R 

LETQ=Q+S 
and then decide what registers to put the 
numbers Q, R, and S in. 

But with variables we can translate the 
single line of Basic into a series of ma- 
chine code instructions. If Q is the vari- 
able at memory location 17001, R is at 
17002, and S is at 17003, then 

LETQ=R+S 
becomes as in Figure 8. 

Get the idea? It may seem a little more 
complicated, but here is the key: you can 
always use exactly the same routine to 
add two variables together and put the 
result in a third variable. To do the same 
thing with three different variables, all 
you have to do is plug different variable 
locations into this same set of instruc- 
tions. 
Remember that machine code has no 



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error messages, and a mistake will prob- 
ably make your computer crash. Then 
you have to unplug the computer and 
start all over again from scratch. Keeping 
track of what you are doing on paper or 
tape may save redoing a lot of work. 

The more you can use "standard" 
chunks of program — like this routine for 
adding two variables together, the easier 
it is to write machine code routines that 
will not crash. 

What is more, in Basic, you do have 
error messages, and, if there is a mistake 
in your program, it usually means you 
have to change just a line to fix the 
problem, then run it again. One easy way 
to write a machine code program is to 
start out by writing the program in Basic, 
making sure it runs properly, then trans- 
lating the program into machine code, to 
get all the advantages of machine code 
speed. 

It may not quite be all the best of both 
worlds, but it comes a little closer. 

Coming Attractions 

There is another big advantage to using 
variables in our machine code programs: 
it makes it easy to send a number into a 
machine code routine. 

We already know how to get an answer 
out of a machine code program. When 
the machine code routine hits the "return" 
instruction, the value in one of the register 
pairs will be returned to Basic. This is the 
HL pair on the 4K ROM , or the RC pair on 
the 8K ROM. 

But suppose we have a machine code 
routine that can draw a line on the screen 
from one point to another. How can we 
tell the routine what two points to draw 
the line between? 

If we have made the coordinates of the 
two points variables in our machine code 
routine, it is easy. Since we know the 
memory locations of the variables, we 
can POKE our coordinates into the vari- 
ables from our Basic program, before it 
reaches the line where the USR function 
sets the computer to work on the machine 
language routine. 

We can also get as many answers as we 
like from a machine code routine, by 
PEEKing at the variable locations after 
the computer has returned to Basic. Usu- 
ally we will not need to do that, but it is 
nice to know we can. 

Next time, we will look at a machine 
code line-drawing routine that is not only 
much faster than Basic, but much smaller, 
too. The Basic version barely fits in a 
computer with 2K RAM, while the ma- 
chine code takes up less than 300 bytes. 

If you have comments or questions 
about machine code programming, or if 
something is not quite clear, let me hear 
from you. Be sure to send along a stamp- 
ed, self-addressed envelope if you need a 
reply. \ 

July/August 1 983 c SYNC 



"CLASS"-MATES 

Two Professional keyboard solutions 
for Timex/Sinclair computers 

FROM SYNERGISTIC DESIGN 

The System Logic KBD- 1 & KBD-2 offer T/S users the highest perform- 
ing computing environment available. Each incorporates a full fifty- 
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ing the KBD- 1 or 2 and your T/S CPU to a variety of applications. A full 
space bar and dual 'SMART* shift keys are included with both units. 

The System Logic keyboards conquer the most beleaguering problems of 
visual saturation. All symbols have been enlarged by 25% and reproduced 
onto a white field providing the greatest possible contrast. 

RFI (radio frequency interference) is non-existant as a result 
of our brushed aluminum and zinc plated steel construc- 
tion. A second'ground plane* is provided to insure 
your system will exceed FCC article 1 5 interference 
standards — engineered performance unattainable 
with 'sprayed metallic* PLASTIC cabinets. With 
our design you'll enjoy monitor-like video quality. 



The serious programmer/professional w 
appreciate 'SMART* electronic features found 
only in our KBD-1 such as single- 
stroke/single-entry electronic shift/shift 
lock. AUTO REPEAT (with fast & slow 
modes) makes repetitive entries effort- 
less. Our data entry ENABLE/ 
DISABLE prevents unwanted key 
entries in your absence. 

Both units will interconnect to 
your T/S CPU without solder- 
ing. Our simple connection 
scheme requires No more 
than a screwdriver! A clearly 
written owner's manual is 
supplied to assist you. 

We think you'll discover a new 
computer with the KBD-1 or KBD-2 
T/S keyboard enhancements! 



P.S. Educators! The KBD-2 is an 
excellent choice for adopting a cost 
effective computer literacy program 
in your institution. 




FEATURES 


KBD-1 


KBD-2 


INTERNAL OR EXTERNAL 
MOUNT 


YES 


YES 


REVERSED SIL K SCREENED 
Kb Y TOPS ON WHITE FIELD 


YES 


YES 


ALLMETAL-ANODIZED 
ALUMINUM £, ZINC PI '• 
STEEL CONSTRUCTION 


YES 


YES 


EXCEEDS FCC RF LEGAL 
EMISSION STANDARDS 


YES 


YES 


58 KEYS WITH FULL SPACi 
BAR 


YES 


YES 


NO SOLDER INSTALLAT ION 


YES 


YES 


DUAl SHIFT KEYS 


YES 


YES 


SINGLE STROKE/SINGLE ENTRY 

RONIC 'SMART' SHU 1 
LOCK 


YES 


NO 


MECHANICAL SHIFT LOCK 


NO 


YES 


AUTO REPEAT ON ALL KL VS 
(FAST & SLOW MODES) 


YES 


NO 


SMART DATA ENTRY ENABLE 
ni'-ARi E WITH INDIC ATOR 






USER MODIFIABLE KEYS 


14 


15 


CLEARLY WRITTEN 

CONVERSION/OPERATION 

MANUAL 


YES 


YES 



CUSTOM INSTALLATION SERVICE: 

As simple as our KBD keyboard enhancements 
are to install some of our customers request that 
we perform the conversion for them. If for some 
reason you would like us to install your 
TS-1000/ZX81 for you we require: 

1 . Your T/S be shipped post paid & insured to us. 

2. An additional $9.95 be included with the 
purchase price to defray installation charges. 



Watch for our full line of T/S enhancements! 



: 



SYNERGISTIC 

HARD/SOFTWARE DESIGN 

P.O. Box 411023 
Chicago, I L 60641 U.S.A. 

Member ACM/IEEE 



Cut and mail to our a 
[Name 


ddress below: 


Address 


City State Zip 




QUANTITY 


MODEL 


PRICE 


AMOUNT 




KBD 1 


89-95 






KBD2 


69 95 




ILLINOIS RESIDENTS 
ADD 6% SALES TAX 
PHONE ORDERS 


SHP/HDL 


4 95 


COD 


295 


(PAYABLE BY 
OR CERTIFIEt 


■RDER 


TOTAL 





91 



Adding a Counter in Hardware Bernard Puerzer 



Sure, we all know computers are smart, 
but can they tell time? Not without some 
work. 

Since getting my computer, I have been 



Bernard Puerzer, 3209 S. Kinnickinnic Ave., 

Milwaukee, WI 53207. 



interested in configuring it to send and 
receive Morse code and display it on the 
screen. The first problem, discussed in 
my article "Machine Code Keyboard 
Scanning" {SYNC 1:4), was to figure out 
how to read the MicroAce/Sinclair key- 
board. This is needed for the transmit 



portion of this task. Next I added 16K 
RAM to hold the program and Morse 
Code message buffers. 

I was now ready to take up the next 
problem: I needed to know how long the 
Morse Code key is held down to deter- 
mine if it is a dot or a dash. I also needed 



. Figure 1. Counter Circuit Schematic. 



A14 



d 



556 
U4 T > 



T 



L-^ 



£> 



04 



In 



^ — JE> 



1 









>- •• 



COUNTERS 
■ svoirs 



da 



T_; 



>» o. 



-L >-., 



T 



T 



LOW COUNT EN - 



— , 



EN 4 » 



, WIC«QACf 

c ONNtr tot 



92 



Parts List. 



RADIO SHACK # 



U1 - 74LS14 




U2 a 74LS08 


276-1822 


U3= 74LS138 


276-1939 


U4 556 TIMER 


276-1728 


U5-7 = 741S161 




U8-9= 747LS244 


276-1941 


THE74lS14and74lS161 


ore available 


ol most electronics ports 


tores. 



July/August 1983 c SYNC 



to know how long the Code Key is up to 
determine if the last character received is 
the last character of the word or not. If it 
is, I need to display a space before the 
next word. 

So I needed a timer to tell the time 
between one event and the next. I did not 
want to add hardware if the same job 
could be done through programming be- 
cause my list of test equipment includes 
an analog voltmeter and that is it. 
Troubleshooting a program seems some- 
what easier to me than troubleshooting 
microprocessor hardware. 

But, in this case, there is no way around 
adding hardware if I wanted an accurate 
counter. The MicroAce/Sinclair has a 
memory location that is incremented 60 
times per second if a display is on the 
screen, but I could not be sure there 
would always be a display. Besides, it 
increments every 16.7 Msec, which is too 
slow for my application. So I needed a 
timer in hardware. Such a timer that can 
run while the computer is doing some- 
thing else can be a benefit in many other 
applications as well. 

Design 

There are several ways to add a hard- 
ware timer to the MicroAce/Sinclair. 

My first attempt was to use a Z80 
Counter Timer Chip (CTC). This really 
quite marvelous device allows the user to 
program any of 4 channels to be either a 
counter or a timer, with an interrupt 
generated when the counter reaches zero. 
I spent many frustrating evenings design- 
ing and constructing a circuit using the 
CTC chip but to no avail. I just could not 
get the MicroAce to program the chip. 
At this point I was convinced that the 
CTC chip that I had was bad. 

So I had to decide whether I wanted to 
purchase another one ($6-15 depending 
on where you order it and how long you 
want to wait for it) or to come up with 
another design. The challenge of a new, 
simpler design (also a flat wallet) won 
out. 

So 1 proceeded to develop a design 
using 74LS161 counters (cheap and easy 
to acquire). First I had to determine the 
smallest and largest time intervals needed. 
For my application I needed intervals 
between 0.1 Msec and 100 Msec. This 
would allow me to transmit and receive 
Morse Code at about 5 to W words per 
minute. 

Then I designed an oscillator that 
would put out pulses of 50/asec (one-half 
the smallest time that I need). This oscil- 
lator would feed a counter comprised of 
three 74LS161 counters which give me 12 
bits output (4 bits per counter). This 
allows the counter to count from to 
4095, Since I am counting 50 /jl sec inter- 
vals I have the ability to count from 50 M 
sec to 204.8 Msec (4096 x 50 Msec). This 




Figure 7. Buffer hoard (see Figure 4). 




Figure 8. Prototype board (16K RAM ami counters) connected to buffer hoard. 




o -w E r TV±)±\ i o p ; { 

A SiD.FTNHJ.KiL:: " 



board in place. 



July/August 1983 c SYNC 



93 



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CONVERSION 



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• Key tops have commands and 
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• Full size space bar 

• Allows touch typing 

• Rear cutout allows any RAM or 



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in 

• Keyboard comes with own cables 

• Keyboard case holds both 
keyboard and computer with room 
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• High impact plastic case with 
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• Easy assembly — no soldering, 
no modifications 

• Measures 10%" x 7//' x 2V 8 " 



GET A BETTER PICTURE WITH SAMW00 MONITORS 



SAMWOO provides a much better picture for your Sinclair 
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Impedance 75 or 
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• 750 Line Resolution 
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model and 8.66" x 
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is twice the time I need to measure, and 
so more than adequate for the job. More 
of these counters can easily be added to 
obtain any number of counts needed. 

The oscillator uses a 556 Timer chip 
that I had in my parts box. This chip is a 
dual 555 timer, but I am using only one of 
the timers. The 555 or 556 chip is readily 
available. A 555 chip can be used, but be 
careful because the pin-out is different 
from the 556 pin-out shown in the sche- 
matic (Figure 1). Since I am using this 
chip as a free-running oscillator, I chose 
the values of RA, RB, and C to cause an 
oscillation of 20 Khz (50^ sec). 

If you want your counter to count at a 
different time interval, use the following 
formula to determine the RA, RB, and C 
values: 



Figwe 2, Duty Cycle of 25%. 



F=4r 

r T 



F( Frequency) 

LM_ 

(RA 4- 2RB) x C 



: _L(time interval) = 
T 



When choosing RA and RB, you must 
also be aware of the duty cycle — the ratio 
of the time the waveform is low (or high) 
to the time it is high (or low). The fol- 
lowing formula determines the duty 
cycle: 

RB 

D= — 

RA + 2RB 



J 



High 75% 



Low 25% 



Figure 3.^ 



Operation 



Address 
4K ROM 8K ROM 



READ or WRITE 4096 32768 



Generates Active 
low signal 

Count reset 



READ only 



READ only 



4097 32769 Low Count EN 



4098 32770 High Count EN 



i_r 



Comments 

Resets all the 
counters to zero. 

Reads the low order 
8 bits of counter. 

Reads the high order 
4 bits of counter. 



For example, the calculations for a count- 
er that counts time invervals of 50 u sec 
(as I need) are as follows: 

i) Choose 0.01 uf for the C value: 
20 x 10 3 Hz = 

1.44 

(RA + 2RB) (0.01 x 10 6 ) farads 

RA + 2RB = 7.2 x 10 3 = 7.2K ohms 
2) Choose 2 resistor values such that 

RA + 2RB = 7.2K 
I chose RA = 3.6K and RB = 1.8K 

3.6K + 2(1.8K) = 7.2K 



3) The duty cycle is: 
1.8K , 9 , 
7.2K ^ 

This means that the waveform is low for 
25% of the time. It will appear similar to 
Figure 2. 

Although not critical, for this appli- 
cation try to keep the duty cycle between 
about 10% and 90%. 

The oscillator will feed the string of 
74LS161 counters which will count up to 
the maximum count (in this case 4095) 




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The CRASH GUARD is made of Heavy Gauge Bronze- 
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July/August 1983 c SYNC 



NAME. 



ADDRESS. 
CITY 



.STATE. 



.ZIR_ 



.CRASH GUARDS" 
Acct. No. 



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a Master Card 

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P O BOX 9543 • RAYTOWN. MO 64133 



Exp. Date 



95 



Figure 5. Low order counter test, . 



then go back to zero and automatically 
begin counting up again. Since the 
output of the counters is always active, 
I must place their outputs on the data 
line only when I want to read them. 
Therefore, I needed the 74LS244 buffers 
that are enabled onto the data bus only 
when their pins 1 and 19 go low. Since 
there are only 8 data lines, obviously all 
12 bits cannot be read at once. So I 
needed to control the counter string in 
groups of 8 bits. In my design a Low 
Count EN signal places the low order 8 



Address 


Decimal 


1643Q 


33 


32 78 


16433 


50 


16 


16436 


14 


255 


164 36 


52 


1 16 


16441 


119 




16442 


6 


9 


16444 


16 


254 


1644^, 


3 5 




16447 


13 




16445 


194 


54 64 


16451 


201 





BACK 



AGAIN 



Instruction 


LD 


ML, 20000 


LD 


( 4096 ) ■ A 


LD 


Ci 255 


LD 


A, (4097) 


LD 


i HL ) . A 


LD 


B, 9 


D-JNZ AGAIN 


ItlC 


HL 


DEC 


C 


jf 


NZ, BACK 


PET 





Comments 

start cf display block 
clear counters 
display counter 

LOAD LOW COUNTER VALUE 
LOAD DISPLAY BLOCK 
DELAY OF 117 t STATES 



bits on the data bus, and a High Count 
EN places the remaining 4 high order bits 
on the data bus. Therefore to get the 



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For versatility this is even better than an EPROM ranks quite high on the list of "must-haves" 

(SYNC Magazine Mar/Apr 83) 



INTRODUCTION 

This memory board is designed to fill the transparent 8K 
block of memory (from 8 to 16K) in a ZX81-16K system 
This area of memory is an ideal place to store, either per- 
manently or temporarily, machine language routines or 
data which are to be used by the BASIC system 

A sample display routine, a program — merging routine, 
and procedures for storing utilities on tape are included 

with the kit 

The use of HM6116LP 2K CMOS RAM memory IC's with 
their own reserve power supply means that routines stored 
in the RAM are nonvolatile — the RAM retains its memory 
even when the ZX81 is switched off or reset Moreover, be- 
ing RAM. the routines you store in the memory are easily 
modified The lithium cell supplied with the. board will main- 
tain sufficient reserve power for almost ten years 



ASSEMBLY 

Complete step-by-step instructions in a 20 page manual 
make assembly of the board easy Construction takes be- 
tween two and three hours The kit (pictured above) is 
complete with a silkscreened solder-masked printed cir- 
cuit board, all capacitors, resistors, transistors, sockets, 
connectors, integrated circuits, and the lithium cell The 
board is supplied with one 2K CMOS 6116LP-3 RAM — it 
will accomodate three more for a total of 8K 

Complete kit with 2K $29.95 

Additional three 61 16LP-3 $16 00 

Bare pc board & manual $13.05 

Assembled & tested with 2K $44.95 

Assembled & tested with 8K $59 95 

Shipping & handling per order $ 1.95 

Send check or money order to the address I 



S> 



96 



HUNTER, 1630 FOREST HILLS DRIVE, OKEMOS, Ml 48864 



30 
40 
50 
60 



t States 



t«13 

t=7 
t=7 
t-13 

t=6 
t = 4 
t = 10 



Basic program 

REM iPUT IN 40 chai^eters to 

hold machine Code) 

LET K-USR( 16430) 

FOR 1=20000 TO 20200 

PRINT PE£*( I ), 

NEXT I 

STOP 



total count value, two read instructions 
are necessary. (See the application section 
below.) 

Decoding 

Three memory addresses that contain 
nothing (no ROM or RAM) are needed to 
map the counters into. On the MicroAce 
with the 4K ROM, the memory from 4096- 
8193 is not used. With the 8K ROM and 
up to 16K RAM, the memory area above 
32767 can be used. This is shown in Figure 
1. Just substitute A15 for A 12 in this 
article for use on the computers with the 
8K ROM. 

I wired up the 74LS138 decoder to be 
enabled when both the MREQ signal and 
the address line A 12 are asserted. Note 
that the LS138 is disabled if A14 is asser- 
ted since this would be an address in the 
16K RAM area (located at addresses 

« r in * "f^i~> r*** 
AUOCVt-OZ/O/J. 

Wiring pins 1, 2, and 3 of the LS138 to 
address lines AO, Al, and A2 gives active 
low signals when the addresses shown in 
Figure 3 are asserted. The LSI 38 decoder 
(address 4099-41 11) has five more outputs 
that can be used for future expansion. 

Since the counters free-count asyn- 
chronous to the MicroAce, we might get 
an inaccurate count (some bits might be 
at the transition between high and low) if 
we read the counter when the count is 
changing. Therefore I gated the Low 
Count EN and High Count EN signals 
with the oscillator output (LS08) to disable 
any counting while the counter is being 
read. No counts are lost because it only 
takes 4 [I seconds to read the counter. I 
also used the 74LS14 Schmitt trigger in- 
verter to give me a sharp edge from the 
556 oscillator. This was probably not 
needed, but, since it worked, I kept it in 
the circuit. 

Construction 

One of the major problems in adding 
hardware to your computer is where to 
put it. I had a wire-wrap prototype board 
to put the counter ICs on, but interfacing 
it to the MicroAce was a challenge. I had, 

July /August 1983° SYNC 



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as I am sure most of you have had, a 
difficult time finding a suitable edge con- 
nector for the MicroAce. Also I wanted 
to buffer the signals on the edge con- 
nector as close to the connector as I could 
to increase signal drive and reduce noise 
pick-up. 

Therefore I built the small buffer board 
with 74LS244 buffers on it, wired as shown 
in Figure 4. This small buffer board was 
mounted with a spacer above the Micro- 
Ace edge connector (I drilled a small 
hole in the corner of the MicroAce circuit 
board, being careful not to drill through 
any circuit runs). Then 1 carefully solder- 
ed the connections from the buffer board 
to the MicroAce edge connector using 
short lengths of wire-wrap wire. The buf- 
fer outputs were soldered to a 37 pin D 
connector also mounted on the buffer 
board. Since D connectors are readily 
available, I felt this was a good choice. 

So now all the edge connector signals 
are buffered except the 8 data lines. These 
are difficult to buffer because they are 2- 
way signals. The buffer must be steered 
to or from the Z80 CPU depending on 
whether a read or a write is being done. 
Since I was not sure what circuitry to put 
on the prototype board, I decided to 
buffer the data lines on the prototype 
board and not the small buffer board. 
Therefore I ran the data lines directly 
from the edge connector to the D con- 
nector. As it turned out, this counter 
circuit alone will work fine without any 
buffering, but, since I also added 16K 
RAM to my prototype board, I felt the 
buffering was needed. I then connected 
my prototype board edge connector to a 
mating D connector with about 10 inches 
of wire. This makes removal of the proto- 
type board from any system quite easy. 

Testing 

So now the counter is wired up and 
power is applied. The prompt comes up 
on the screen, so I know at least the 
MicroAce still works (that is reassuring 
anyway). But how do I test the counter? 

I wrote two short programs (Figures 5 
and 6) that are a combination of machine 
code and Basic. Load in the machine code 
starting in location 16430 (location 16520 
in 8K ROM systems). The first Basic 
statement should be a REM statement, 
long enough to hold the code then scrol- 
led off the screen with PRINT 
statements. 

The program in Figure 5 tests the low 
order 8 bits of the counter. The program 
resets the counter then reads the counter 
every 50.4 \x sec, displaying the result. 
The display should go from to 255 but 
will skip a number every so often since 
the counter counts at exactly 50 ptsec but 
the program reads the counter every 50.4 
M sec. This was good enough for a 
functional test. I did not want to fine tune 

98 



Figure 6. High order counter test. 



Address 


Decimal 




Instruction 


Comments 


lo4 30 


33 


32 


78 




LD 


HL, 20000 


START OF DISPLAY BLOCK 


16433 


50 





16 




LD 


(4096), A 


CLEAR COUNTERS 


1*436 


14 


255 






LD 


C* 255 


DISPLAY COUNTER 


1643S 


22 


13 




BACK 


LD 


D. 13 


DELAY LOOP 




56 


2 


Xo 




LD 


A. t4098> 


LOAD HIGH COUNTER VALUE 




230 


15 






AND 


00001 11 IB 


MASK OUT UPPER 4 BITS 


16445 


119 








LD 


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LOAD DISPLAY BLOCK 


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RET 




Basic program 



the program to read the counter every 50 
ju sec. The time a program takes can be 
calculated by counting the number of t 
states each machine code instruction 
takes. On the MicroAce/Sinclair, 1 t state 
= .308 Msec. 

The program in Figure 6 checks the 
high order 4 bits of the counter. It resets 
and reads the counter every 12.808 Msec, 
displaying the result 200 times. The dis- 
play should go from to 15 and increment 
every 12.8 Msec. If the low order counter 
works but the high order counter does 
not, check the ENT and ENP connections 
(pins 7 and 10) on the high order counter. 

Application 

To use this counter most effectively, it 
is best to reset the counter at the begin- 
ning of the time interval to be measured, 
then read the counter at the end of the 
time interval. This will give you the num- 
ber of 50 fi sec intervals that have evnired 
Remember that, when the counter reach- 
es its limit (4095), it goes back to zero and 
starts counting again. Therefore the time 
interval that you measure cannot be larger 
than 4096 x 50 u sec = 204.8 Msec. If it is, 
either change the 556 oscillator resistor 
values to obtain a slower frequency or 
add more 74LS161 counters to your 
circuit. 

The two most convenient ways to read 
the counter are: 

1) In machine code, load one of the 
register pairs, for example, HL, as follows 
for 4K ROM: 

LD A,(4098) ;read high order count 
LD H,A 

LD A,(4097) ;read low order count 
LDL,A 

Now register pair HL contains the full 12- 
bit count, 

2) In Basic, read in the high order 
count, multiply it by 256, then add it to 
the low order count. For example, for the 
4K ROM: 

LET A = PEEK (4098) 

LET B=A*256 

LET C= PEEK (4097) 

LET C=PEEK (4097) 

LETD=B+C 

For the 8K ROM, change 4097 to 32769, 



10 

20 

30 

50 
60 



t States 



t = 7 

t*i3 

fe-4 
t-7 

t*7 

t=13 

t=7 

fc-10 

t=6 
t«4 

t = 10 



REM (PUT IN 40 characters to 

hold Machine Code. 

LET k=USRU6430> 

FOR 1=20000 TO 20254 

PRINT PEEK* I ) 

NEXT I 

STOP 



.Figure 4. Interface board. _ 



+$v 





AI- 


4 

H 

1 1 




A2- 




A3- 




A4- 


1 \ 


OS 


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o 


A6- 




H 




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m 







2 

O 

u 



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WR _1 
MREQ— 

RFSH-7 

Ml- 11 



NOT 
USED 




DC 
< 

O 

CQ 



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O 
h 

o 

OS 

— 

o 

h 



and 4098 to 32770. above. The number in 
variable D is the full 12-bit count. 

We hope that you will be able to use 
this hardware timer for your purposes— It 
can be used for anything from designing 
an alarm system to displaying the correct 
time while your program is running. Good 
luck in your timing applications. Now you 
can tell your doubting friends that com- 
puters are really smart; just look, they 
can count and, with a little programming, 
they can even tell the time! 5i 



July/August 1 983 c SYNC 



BYTE-BACK modules 



64-K MEMORY $129. 95 



W^AcFgg 



BYTE-BACK'S MD-1 

MODEM $119. 95 

ASSEMBLED & TESTED $149.95 



Use your phone to connect your "LITTLE" computer to the 
"LARGEST" computer networks in the world. With BYTE- 
BACKs MD-1 MODEM connected all you do is dial a phone 
number {usually local), press a few keys and watch the data 
appear on your TV screen. (Software is included) This 
MODEM can be used in either the "originate" or "answer" 
mode with selectable baud rate. 

You can have immediate access to: 

UNIVERSITY COMPUTERS, DOW JONES, UPI 

COMPUSERVE PACKAGE WITH 5 FREE HOURS ONLY $34.95 

As an extra bonus an RS-232 port is provided to allow you to 
drive all standard RS-232 peripherals. (75 to 9600 Baud.) 



BYTE-BACK'S BB-1 

CONTROL MODULE 
$59. 00 In Stock! 

• 8 Independent Relays 

( with LED status indicators) 

• 8 Independent TTL Inputs 

( with Schmitt trigger buffers) 



OTTOSS^ 




• By using a single POKE command you 
can change and latch the status of each of 
the 8 relays. 

• Your computer can read the status of all 8 
inputs by the use of a single PEEK 
command 

• A comprehensive manual is included that 
has complete application details 

• More than one BB-1 can be used at a time 



$139. 95 ASSEMBLED & TESTED 



In Stock! 

With 
BATTERY BACKUP 

the "ULTIMATE MEMORY" UM-64 
FEATURES: ^ 

• Battery backup I s * ^ 

• PROM/ROM socket 

• Reset Switch. 

• BYTE-BACK EXLCLUSIVE FULL 64-K 

The 0-8K area is available. You can execute a copy 
routine (provided) to copy the TIMEX ROM into the 
0-8K area of RAM then flip a switch and you have 
your operating system in RAM. You can modify it 
and create your own customized operating 
system. Full details, examples & programs included. 

WHY PAY MORE FOR LESS FEATURES? 
GET THE "ULTIMATE MEMORY" 
BYTE BACKS UM-64 



16K MEMORY UM-16 $59.® 5 # $69 « assembled & tested. 



kit 



Battery backup, reset switch, PROM/ROM 
socket PLUS. ... 1 year, 100% trade-in credit 
towards the UM-64. 



RS-232 Module $59. 95 

ASSEMBLED & TESTED $69.95 
Allows you to connect your computer to all RS-232 printers & terminals 



ALL MODULES CARRY 90-DAY WARRANTY 

TRY BYTE-BACK MODULES FOR 10 DAYS WITH NO OBLIGATION 



BYTE BACK 

KEYBOARD 

$89. 95 

We use the same 
key switch found in 
the expensive com- 
puters such as: 
Hewlett Packard, 
Texas Instru- 
ments, Atari, DEC etc The multi-colored key caps are the same type 
used on the IBM Personal Computer, but with the TIMEX ledgens. 

FYPFRIFNHF OIIAI ITY 




1 Shipping and Handling $4.95 
ORDER PHONE (803) 532-5812 
ITEMS ORDERED: 



Bill My D Am. Exp 



Exp. Date 

Name 

Address _ 



DVtsa DMC 
Checks Accepted 

Card No. 



City/State/Zip 

Phone 



Dealer Discounts Available 

Mai To BYTE-BACK CO. 

Rt. 3, Box 147, Brodie Road 



Buyer's Guide Supplement 



This section is a supplement to our Buyer's Guide issue (May /June 1 983}. We have 
included the categories for which we did not have space in the Buyers Guide (Astronomy, 
Horse Racing, Hangman, and Golf) and the entries which were received too late to be 
included. A limited quantity of the Buyer's Guide issue will be available at the back issue 
price of $4. 00 per copy on a first come, first serve basis. 



Improving Your 
Computer 

Computer Practice Keyboard Co. 

Portable Keyboard 
$4.95 pp.; 2 for $8.50. 

Learn and practice your keyboard while away 
from your computer. Regular typewriter key 
positions and special functions. Printed on 
sturdy 8 1/2x11 stock to fit standard binders 
with plastic lamination. Available for Timex, 
Apple, Atari, TRS-80, TI 99/4, IBM, Com- 
modore, Wang, Xerox, Osborne, and others. 
Specify which computer keyboard you want. 

Datametrics 

ZX81 Dust/Dirt Cover. £3 plus s&h. 

Covers available in black, red, brown, green; 
made in durable padded P.V.C. with facility for 



tn.au anu iat 



of dirt. 



Daydesign 

My Type 

16K RAM. Cassette: $8. 

Teaches touch typing on your ZX81 key- 
board. Features include key location, review, 
token command drills. Mistakes and WPM given 
at end of each lesson, 

Big -Key Legends. $7 per set. 

Dry transfer keycap graphics in red and black ; 
identical to those on the ZX/TS keyboard. For 
use on full size keyboards with standard 1/2" 
key caps. 

Dynamic Designs 

Control Module. $27.50 plus $2 s&h. 

A powerline switch, power "ON" indicator, 
LOAD/SAVE isolation switch with LOAD level 
monitor and Reset control. Isolation switch 
prevents feedback during program SAVE. Reset 
allows recovery from crashes without powering 
down peripherals. 2 3/4" x 2 x 1 1/4". Can be 
mounted on top of computer or used alongside . 

Reset Control. Kit: $4.50 pp. 

Add system Reset capability to permit quick 
recovery from crashes without powering down 
peripheral equipment. Control attaches to com- 
puter with two wires. Complete instructions for 
mounting and use. 



N. J. Gipson 

Self-Starting Program Unlocker 
Cassette: $13.95 pp. 

No more worries about program tapes you 
cannot back up; no more programs you cannot 
LIST and modify. Changes any tape program to 
allow Basic commands immediately after 
LOADing. Lifetime Guarantee. 

Laserscan Electronics Corporation 

16K extender RAM Pack. 
Kit: $39.95; assembled: $44.95. 
PC Board with connectors: $24.95. 

Highly crash resistant RAM pack that can be 
mounted inside the computer under the key- 
board or plugged directly into the rear con- 
nector. Requires no extra power supply; comes 
with a special high pressure edge connector 
employing gold plated, bifurcated contacts that 
will nui allow die sysieni 10 crash due to vi- 
brations. Allows the use of the printer. 

R-Tek 

CopyCass. $19.95 plus $2 s&h. 

Software backup system interfaces two in- 
expensive cassette recorders to provide a reli- 
able method of tape to tape transfer of any 
program compatible with ZX80, ZX81, and 
TS1000 computers. SASE for free brochure. 

G. Russell • Electronics 

Key Load 

16K RAM. Cassette: $10. 

Unlocks those unSAVEable, unLISTable cas- 
sette programs. After LOADing this short ma- 
chine language program, any TS/ZX cassette 
program subsequently LOADed instantly be- 
comes SAVEable and LISTable. Now you can 
make a clean, easy to LOAD, back-up copy of 
that valuable cassette program. 



Extending Your 
Computer 

Ener-Z 

Report Generator 
$69.95 plus $3 s&h. 

Data acquisition and control board: Cen- 
tronics printer interface supports LLIST, 



LPRINT, COPY; real time clock with battery 
backup ; 8 bit I /O ports ; CMOS A/D converter. 
Features: Bus connector for RAM pack; ROM 
resident firmware; I/O mapped. 

Intercomputer Inc. 

Flexible Ribbon Connector (PL7016). $17.95. 

A flexible ribbon for connecting any Memory 
Expansion, Softbox cartridges, and Intercon- 
troller to your TS 1000. Prevents the usual system 
crashes caused by RAM pack movement. 

lntercontroller (PL7013). $34.95. 

Put your TS1000 to work around the clock 
and do any number of tasks automatically (e.g., 
turns on /off your lights, motors, waters your 
lawn). Just plug lntercontroller into your com- 
puter and program each of the three switches 
individually. Software programmable with time 
intervals trom tractions ot seconds to days. 
Connect up to four lntercontroller units to your 
computer with a Softbox. 

Kabre Electronics 

Automatic Repeat Function. $15.95 pp. 

Module with built-in self -test LED, automatic 
and continuous character input. Saves time and 
editing, 

MAV Mlcroproducts 
EPROM Programmer/Reader 
$64.% plus $3 s&h. 

Uses two 4K 2732 EPROMs in the 8-1 6K slot. 
Housed in slim plastic lie flat case with ribbon 
connector and expansion port making it com- 
patible with RAM packs, printers, etc. Uses 
zero insertion force sockets for programs that 
failsafe load in seconds instead of minutes. 
Assembled and tested, with one EPROM. Extra 
EPROMs: $4.95 each. 

Spyder Electronics 

The Spyder Character Board 

Kit: $24.50; assembled: $29.50; bare board: 

$14.50; $2.50 s&h. 

A 4K (2K populated) memory expansion that 
allows changing of the ZX81/TS 1000 character 
set; in the transparent region between 12 and 
16K ; may be populated with 61 16 RAM or 271 6 
EPROMs. Spyder offers EPROM programming. 
Full documentation and two programs on cas- 
sette are included. 



100 



July/August 1983 c SYNC 



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Time works. Inc. 

Computer Control Center. $29.95. 

On/off switch eliminates constant plugging 
and unplugging. Accommodates all brands and 
sizes of RAM packs and a 13" screen monitor; 
angled for maximum display and viewing. Pock- 
ets for tapes ; openings for TS Printer and cas- 
sette deck hookups. High impact, molded poly- 
styrene case gives a sleek, sophisticated, profes- 
sional look. Cords and wires hidden under the 
unit. 3 5/8" x 20" x 14 1/2". 



Programming Your 
Computer 

A + Associates 

Understanding Sinclair Basic 

16K RAM. Cassette: $10 plus $1 s&h. 

Fully demonstrates all of the Sinclair Basic 
commands and statements. You control the 
speed of the demonstration. Repeat each pro- 
gram as you need. If you are having difficulty 
with the manual, this program will simplify your 
problems. 

TS/Basic. $3 plus $1 s&h. 

A Basic programming form. High quality 
erasable bond paper 8 1/2 x 11. 24 line screen 
mapped on the front; 22 line screen on the back 
with coordinates; varied line density for legi- 
bility; area for notes and variables. 

Blocal Software 

(See Directory of Suppliers for prices.) 
Base-N 

Convert numbers from one base to another 
quickly; up to base 36. Includes decimal frac- 
tions. 

Menu 

Tape loader program, menu driven. Add, 
change, delete, sort, list. 

Note-pad 

Full screen editor; supports cursor movement 
up, down, left, and right. Multipage storage. 

Daydesign 

My Type 

16K RAM. Cassette: $8. 

Teaches touch typing on your ZX81 key- 
board. Features include key location, review, 
token command drills. Mistakes and WPM given 
at end of each lesson. 

Intercomputer Inc. 

Assembler /Debugger ZXAD (PT4003) 
16K RAM. $18.95. 

Write machine code quickly and easily with 
this professional quality twopass assembler. Uses 
Zilog mnemonics with labels and symbols, 8 
pseudoops, syntax checking, display or print 
listing with commands. Debugger includes 
examine/modifying, breakpoint with register 
display, line renumbering occupies 7K. Com- 
prehensive multipage manual. 

Memo tech 

Memopak Assembler 
EPROM: $49.95 plus $4.95. 

Code and edit a source program in Z80 
language and then assemble it into machine 
code. Editor mode allows you to code directly 
in the right format, manipulate individual lines, 

July/August 1983 c SYNC 



and control the exact placing of source and 
machine code. Routines may be merged or 
listed. Handles all standard Z80 mnemonics; 
numbers in hex or decimal; comments; and 
user-selected labels. On EPROM and plugs 
directly into your computer. 

Nanos Systems Corp. 

ZX80, ZX81, and Timex /Sinclair 1000 System 
Reference Card. $5.95. 

Quick summary reference card with: Graph- 
ics, Basic statements, Basic commands, Basic 
functions and derived functions, special char- 
acters and operators, screen layout, all codes 
panels (0-255), selected ROM calls, tips on using 
FOR-NEXT, IF-THEN statements, ZX80 and 
ZX81 memory maps, error codes, Z80 timing 
chart, short version of Z80 language, entire Z80 
language OP-CODE. Accordian style card with 
20 pages on 10 panels. 

G. Russell - Electronics 

Key Load 

16K RAM. Cassette: $10. 

Unlocks those unSAVEable, unLISTable cas- 
sette programs. After LOADing this short ma- 
chine language program, any TS/ZX cassette 
program subsequently LOADed instantly be- 
comes SAVEable and LISTable. Now you can 
make a clean, easy to LOAD, backup copy of 
that valuable cassette program. 



Using Your Computer: 
Programs 

Astronomy 

Bug-Byte Software 

Constellation 

16K RAM. Cassette: £8. 

Turn your ZX81 into a telescope. Program 
produces a simulation of the night sky as seen 
from any position on Earth at any chosen time 
this century. Point your telescope in any dir- 
ection, more it around, zoom in or out. Stars 
displayed by magnitude or constellation. 

Gladstone 

Solar System (Z44) 

16K RAM. Cassette: $11.95. 

A databank on the cosmos. Facts, interre- 
lationships of the planets, their moons, the sun, 
artificial satellites, the constellations. 

Kamel Technology 

All 3 astronomy programs for $24.95. 
Planetfinder 
16K RAM. Cassette: $9.95. 

Computes the right ascension and declination, 
constellation planet is in v brightness, distance 
from earth, angular diameter, and phase. For 
any planet, any date. 

Suntracker 

16K RAM. Cassette: $9.95. 

Computes position of sun, sunrise, sunset for 
any location, any time. 

Moontracker 

16K RAM. Cassette: $9.95. 

Computes position of moon, rising and setting, 
for any location, any time. 



SINWARE provides these quality 
machine code programs for the ZX81/ 
TS1000: 

STEP 

STEP provides line-at-a-time execu- 
tion of your BASIC programs and 
shows you the display and variable 
values to pinpoint programming er- 
rors. Set line breakpoints, loop break- 
points, or conditional breaks for fast 
testing of long routines. STEP oc- 
cupies 3K at the top of your 16K RAM 
as you write and test new programs. 
Detailed documentation. The final 
solution for BASIC bugs. 

Z-TOOLS 

Z-TOOLS lets you merge programs 
from tape, renumber lines (including 
GOTOs and GOSUBs) for neat listings, 
copy and delete program blocks for 
quick restructuring, or verify tape con- 
tents against memory to eliminate pro- 
gram losses. Supplied in two versions, 
for the top of a 16K RAM pack or for 
the 8-10K block of expanded RAM. 

HOTZ 

HOT Z disassembles, debugs, and lets 
you copy and edit machine code pro- 
grams. If you can move a cursor 
around and understand hex numbers, 
you can use HOT Z almost at once. 
Provides beautiful assembly listings, 
addressable cassette functions, runs 
your ZX printer (or Memotech l/F), 
even disassembles the ZX floating- 
point language. You owe your ZX/TX 
a fresh dose of HOT Z. 

Z EXTRA 

Z EXTRA is a display manager and 
data filer that lets you enter text, data 
or pictures directly to the screen and 
save them in groups in memory, on 
tape or in print. Display them sequenti- 
ally or in scrolls through one another or 
use them in your BASIC programs. 
Give your computer a completely new 
personality with Z EXTRA. 

PRICES Add $2.00 for postage 

STEP cassette $14.96 

Z TOOLS Cassette $14.95 

Z EXTRA Cassette $19.95 

HOT Z . . 16K or 32K + Cassette $19.95 
HOT Z-E... Four 2716 EPROMs $40.00 

SINWARE 

Box 8032 
Santa Fe, NM 87504 



101 



cottage 
.technology 



ZX81/TS 1000 HARDWARE 



□ 

□ 
□ 



REVERSE VIDEO-Converl your TIMEX/ Sinclair 
to the standard white letters on a dark background 
for better readability and a more professional ap- 
pearance Fits inside case with only 4 solder con- 
nections $10.95 
VIDEO MONITOR OUTPUT-A small pigtail 
allows you to connect your TIMEX/ Sinclair to a 
NTSC-compatible standard video monitor tor a 
crystal clear display Parts and instructions $4.95 

THE LAST CASSETTE/1 6K Fix-Having pro- 
blems with SAVE/LOAD when the 16K module is 
attached 7 This smalt modification reduces ram 
pack noise at the signal source Kit and instruc- 
tions $2 95 



ZX 81 /TS SOFTWARE 



□ 

□ 

□ 
□ 



ACZ GENERAL LEDGER -Computerize your 
small business accounting This system prepares a 
full set of financial statements and keeps a record 
of the ledger transactions it can handle any com- 
bination of up to 400 entries and accounts per ses- 
sion, sorts 150 entries in 10 seconds, and works 
with or without a printer 16K. $29.95 

ACZ CHECK REGISTER- Does more than just 
balance your checkbook It summarizes expenses 
by account so it's easy to see just where your 
money is going This program can be used atone, 
or as a companion to the ACZ General Ledger 16K 
$1095 
ACZ EASY GRAPH takes the tedium out of bar 
graph preparation It automatically calculates the 
correct scale, offers continuous updates, and 
stores 4 different graphs in one program. 16K 

$9.95 
YOU'RE THE BOSS -A business game As 
president of your own company, you make the pro- 
duction and marketing decisions that lead to suc- 
cess or bankruptcy A strategy game for 1 or 2 
players 16K $10.95 



IMPROVE YOUR PROGRAMMING 



□ 



Looking for ways to improve your BASIC program- 
ming techniques 7 We've listed 10 of our best 
routines with examples of how to use them in your 
programs One routine makes it ■impossible" to 
etitei me wrong aaia Anotner aligns columns of 
numbers by the decimal point Others allow single 
keystroke menu selection, sorting, rounding, and 
more 



$4.95 or FREE 

with any software purchase. 



COTTAGE TECHNOLOGY 

5720 W Little York S 
Houston. TX 77091 



REVERSE VIDEO 



MONITOR OUTPUT 



CASSETTE FIX 



ACZ GENERAL LEDGER 



ACZ CHECK REGISTER 



ACZ EASY GRAPH 



YOU'RE THE BOSS 



4 95 



10 BEST ROUTINES 

FREE with any software purchase 



EA. S&H 



295 



1 50 



AMOUNT ENCLOSED $ 



Texas residents add 5% sales tax 

For free catalog send a self-addressed stamped envelope 

NAME 

ADDRESS 

CITY 

STATE . ZIP 



Robert C. Moler 

Astro-Utilities 

16K RAM. Cassette: $14.95. 

For amateur astronomers. Calculates Julian 
date, siderial time; rise/set times; altitude/ 
azimuth; procession of celestial objects; and 
more. Menu driven; instructions. 

Orbit 

16K RAM. Cassette: $9.95. 

An astronomical demonstration program for 
educators. Draws elliptical orbit shapes based 
on eccentricity. Also calculates and produces 
animated display of orbital motion. 
Instructions. 

Galaxy 

16K RAM. Cassette: $9.95. 

An astronomical demonstration program for 
educators. Draws normal and barred spiral gal- 
axies from input parameters. Galaxies may have 
variable orientation from face-on to edge-on. 
Choice of two spiral algorithms. Instructions. 

Relativity 

16K RAM. Cassette: $11.95. 

An astronomical demonstration program for 
educators. Graphically shows effects of relativ- 
istic velocities on length of a spacecraft plus 
time dilation effects. Demonstrates the "twin 
paradox" on trips to Alpha Centauri and the 
Andromeda Galaxy. Instructions. 

Planets 

16K RAM. Cassette: $9.95. 

An astronomical demonstration program for 
educators. Calculates and displays positions of 
the planets around the sun for a date or series of 
dates. Can plot planet distances to scale and 
include a comet. Instructions. 

Print-Planets 

16K RAM. Cassette: $11.95. 

An »jctr/-vT»r»m!rK3i ^srnonstrstiort TC^rsm 
which uses the hi -res capabilities of the ZX 
printer to plot the positions of the planets in 
their orbits. Menu driven with 4 plotting options. 
Orbits are delineated and planets are plotted 
with their astronomical symbols. Instructions. 

BobWoish 

Telescope Design 

2K RAM. Cassette: $4.95; listing: $2.95. 

Asks for desired objective diameter and 
f /ratio, inputs physical dimensions and optical 
data for a Newtonian reflector optical assembly. 
Saves hours of calculation. 

Z-West 

Celestial Locator 

16K RAM. Cassette: $7.95 plus $1 s/h. 

Provides the amateur astronomer with 
AZ/ALT positions for any given celestial 
source. Radio astronomers can rapidly adjust 
antennas with the location positions provided 
by this program. Celestial Locator /ZX99 is also 
available with this tape to printout monthly 
positions on RS232 printers. 

Graphics 

Biocal Software 

<See Directory of Suppliers for prices.) 
Display 

Several different graphics techniques are used 
to create pictures and plots. 



Skeet. IK RAM. 

Turn your computer into a drawing board. 
Visible flashing cursor even while retracing. 

Computer Software Associates 

Graphics Starter Pack 
IK RAM. $14.95. 

4 programs: Kaleidoscope, Large Print, 
Medium Print, Draw-A-Picture. Explains and 
discusses GOSUB, INKEY, PRINT AT, PLOT 
and UNPLOT, the way the ZX81 stores char- 
acter shapes (and where), the decomposition of 
the decimal to binary and how to use the cursor 
to "draw" on the screen. 

Multigraphics 23 
16K RAM. $14.95. 

Menu-driven package gives full control of 
ZX81 graphics. Includes: Comprehensive 
sketch pad function, small, large and jumbo text 
functions. Two packages of mixed graphic and 
text displays or one animated display. Edu- 
cational/tutorial, business graphics functions for 
shop-window advertising displays. 

Ksoft 

TS-Art 

16K RAM. Cassette: $12.95 (s&h: $1.50 U.S., 

$2.50 abroad). 

Graphics program and Logo-style educational 
tool. Indirectly teaches concepts in arithmetic, 
geometry, and computer science. Work with a 
pencil, eraser, about 120 brushes, a video in- 
verser and a "flicker" by moving them in 8 
directions or along circles and lines. Set any 
background. Define new graphics commands. 
Expand, compress, or rotate. Save or print art- 
work. 

Memory Master 

Instant Art 
16K RAM. $10.95 pp. 
"Paint" pictures on the screen using two brush 

■*<mm> ~™A fU rsn „„!«-„ (U1~~V ...u:*~ ~_4 \ 

Paint in 8 directions and change brush size or 
color at any time with a press of a key. Directions 
contain a simple , single line change which allows 
you to paint with any character on the keyboard. 
Option for painting random symmetrical pat- 
terns. 

Data Entry/Retrieval 

Biocal Software 

(See Directory of Suppliers for prices.) 
Catalog 

Card file system. Uses indexed sequential 
access method (ISAM). Vary key and record 
sizes. 

Clients 

Mailing list keeps track of your clients using 
ISAM techniques to maintain the file. Sales/ 
Dates. 

Histogram 

Category maintenance, transact data entry, 
category plots, totals, and averages per cate- 
gory. 

ISAM 

Indexed Sequential Access Method subrou- 
tines allow you to retrieve your records via 
alphanumeric keys. 



July/August 1983 c SYNC 



50 



4. a 



Actual Screen Copy 
of VOTEM In Action 

The y-axis is temperature in 
degrees C. The x-axis is 
time. Each unit equals 5 
seconds. The graph starts 
with the temperature probe 
in ice water. At time =9 the 
probe was placed in air at 
room temperature. At 
time =25 the probe was 
placed in a cup of hot water 
and at time=31 the probe 
was again placed in air at 
room temperature. The 
program used only 2K of 
memory. Imagine what you 
could do with 16K! 

WE ALSO HAVE THE 
HUNTER BATTERY 
BACK-UP MEMORY 

• Up to 8K of nonvolatile 
memory 

• 6116 CMOS RAM or 
2716/32 EPROM 

Complete kit 

with 2K $29.95 

Assembled with 

8K $59.95 

Shipping (memory 

only) $ 1.95 

Down East Computers 

PO Box 3096 
Greenville, NC 27834 



Library 

Keep track of your books. Search list for 
author, title, publisher. 

Orders 

Order tracking system with mailing list, main- 
tenance, sort, report, plot. 

Reminder 

Calendar and appointment book. Make, can- 
cel, change, list appointments. Uses ISAM file 
technique. 

L. Harmon 

Mail Master 

16K RAM. Cassette: $6.95. 

Mailing list program . Menu<lri ven ; auto run . 
Includes full edit and search routines. Supports 
any ZX/TS compatible printer. Options include: 
add names, search/view, edit, search/print, 
prints complete list, inform, and others. Com- 
prehensive user's manual. 

Data Master 

16K RAM. Cassette: $6.95. 

Versatile data storage /retrieval program. In- 
cludes full edit and search routines. Supports 
any ZX/TS compatible printer. Ideal for the 
small businessman or homeowner. Includes 
comprehensive user's manual. 

Chart Master 

16K RAM. Cassette: $6.95. 

Program generates and analyzes bar charts. 
Printed output if desired. Ideal for the small 
businessman or homeowner. Includes full in- 
structions. 

Silicon Valley North 

Grade Roster 

16K RAM. Cassette: $7.95 plus $1 s&h. 

Complete permanent gradebook exam and 
course performance analyzer. High capacity. 
Scores displayed in table with analysis of mean, 
standard deviation, variance, high /low score, 
frequency distribution for each activity. Final 
or part term student rankings based on weighted 
exam scores. Plus other useful options, 

Stuart Software 

Press Release Mailing List. $25. 

1 -Across mailing labels in Zip Code order. 
Mailing list for sending out press releases for 
computer-related products. Contains about 400 
periodicals. Ideal for businesses seeking to max- 
imize the "free advertising" which occurs when 
a press release is printed in the "New Products" 
section of a magazine or newsletter. 

Financial 

Biocal Software 

(See Directory of Suppliers for prices, i 
Bar-Chart 

Watch the fluctuations in your expenses. Plots 
numeric arrays using a scaled histogram. 

Checkbook. 16K RAM. 

Balance your checkbook. Outstanding 
checks, deposits, current balance. 

Loan 

Generates loan payment schedules. Check 
interest vs. principal. Evaluate time payments. 






pleasanjrees 

ICK OF THE CROP FOR 1 

PROGRAMMING 
FORM PADS 

Afl lines including edit lines 
Not half sheet— full e'Aim 
premium erasable paper 
50 sheets per pad 
Free coded example of 
W.C Fields 
■ Window Card tor easy reading 

PADS 2.19 ea. { + 75/pad p&H) 




16K 




Zxak-man! 



At last a version with attention to detail Zxak 
is a cute cubical character that winks and 
chews as he moves 5 levels and 4 ghouls 
make for strategy game playing All in smooth 
M.C. animation A must 14.95 




ofXon! 




Scrolls 3 dimensionally. Your shadow follows 
below as you avoid hazards Various 
weaponry help you rack up points Most 
impressive graphics your machine can 

exhibit. In M.C 19.95 

Please add 1 50 per cassette postage & handling 

GRAPHICS A to Z 

This invaluable manual concentrates on graphic 
programming. For novice or pro with '81/1000 or 
Memotech's HRG there's something exciting: 



ForHRG 

• Terms dictionary 

• Plot 3-D (cover) 

• MC control (speed 
screen fill 34x) 

• HRG disassembly 

• New call addresses 



lany techniques for Baste programs Later chapters take you 
carefully into Machine Code Tired of pulling your hair out over 
other Machine Code texts 9 These chapters are well-wntten 
with simple examples to get you into the world of fast graphics 

17.95 ppd 





July/August 1983 c SYNC 



103 



LOVE AT 
FIRST BYTE 




C-20 Magazine has something 
for every TS-1000 or ZX-81 
owner to love each month. We 
offer 2K and 16K programs in 
each issue. 

Educational Software 

Software for your Home 

Games Games Games 

Editorial Section 

The C-20 Mailbox 

A Big Time Saving Value. Less 

than $4.99 per issue with over 75 

programs per year. That's less 

than 80 cents per program! 

C-20 Magazine comes each 
month with ready to run soft- 
ws*" rt No time wasted t v/n ' nn ' n a 
program listing. 

1 Year (12 issues) $59.95 

6 Months (6 issues) .... 38.95 
Kansas residents add 3%. First 
class mail included in North 
America. All others add $10 per 
subscription. 



C-20 



vuia/ztfirie 



P.O. Box 3801 
Wichita, Ks. 67201-3801 

24 Hr. ToH Free Order Line 
1-800-835-2246 Ext. 240 

or in Kansas 
1-800-362-2421 Ext. 240 

VISA and MasterCard 

Dealer Inquiries Invited 



Sales 

Inventory sales analysis shows you what is 
selling best, how many were sold, and total sales 
dollars. 

Market Software 

Deduc-table 

48K RAM. Cassette: $14.95. 

A menu driven program to track a year's 
worth of tax deductions. Twenty user defined 
categories. Each category may contain 25 
entries. Entries include date, description (com- 
ments), and dollar amounts. Review individual 
files, or totals Y.T.D. Self -starting, self -naming, 
self -saving. Full support by SASE. 

Free Update 

Current owners of Financial Record Keeper 
( 16K ) or Financial Record Keeper Plus (48K) 
may write for listing of newly added Tax De- 
duction Review application to flag tax deduc- 
table payments during the normal entry pro- 
cedure and review them at any given time. (Note : 
Current cassettes being mailed incorporate this 
application.) Send SASE. 

Home Budget Planner 
16K RAM. $10.95 pp. 

Computes and compares amount spent versus 
budget for a 13 month period. 20 user definable 
budget categories and 10 separate categories 
for income and deductions. Displays and prints 
out data by the month or year to date. Bar 
charts are drawn from monthly averages and 
show the year at a glance in graphic detail. 
Menu driven with easy edit and update. 

Memotech 

Memocalc 

EPROM: $49.95 plus $4.95. 

Spreadsheet analysis to assist with reports 
and financial forecasts. Performs complex num- 
ber crunching routines with ease. Memopak s 
64K RAM gives a table of up to 7000 numbers 
with up to 250 rows or 99 columns. Quick 
revisions. The CALCULATE command reeval- 
uates and displays the information. Tool has 
been generalized to perform interactive calcu- 
lations in numerical tasks. On EPROM and plugs 
directly into your computer. 

Sikes Software 

Checkmaster 

16K RAM. Cassette: $16.95. 

Enter and store over 450 transactions per 
load. Menu driven. Allows you to list, search, 
add, save, graph. Special graph feature allows 
you to graph checking balance 9 dates at a time, 
starting with any desired date. Search for credits, 
dates, and debts. Graph may be scaled and 
labeled as desired. 



Stocks 

Air Capitol Software 

Call/Put Stock Options Analysis 
16K RAM. Cassette: $25. 

Make objective strategy decisions. Requires 
only current options data from popular financial 
publications. In-depth analysis using extension 
of Black -Scholes model. Nine options per run 
ranked by potential profit, loss, expected return. 
Easy-to-use; full screen edit. Documentation. 



Biocal Software 

(See Directory of Suppliers for prices.) 
Stock. Cassette only. 

Learn the mechanisms behind the stock mar- 
ket. Includes buying on margin, short selling, 
convertible preferred, options to buy via war- 
rants. Invest. 

Memory Master 

Stock Analysis and Portfolio 
16K RAM, Cassette: $10.95 pp. 

2 programs: Program 1: Takes data on any 
stock, computes total cost including broker's 
commission, and computes the result of any 
number of call options entered including gain, 
yield, time held and more. Program 2: Holds 
information on up to 10 stocks and computes 
gain, yield, etc. Displays a composite view of all 
stocks held. Easily updated, changed, or 
deleted. 

Word Processing 

Bob Flngerle 

Textwriter WOO 

16K RAM. Cassette: $11.95; listing: $5.95. 

Text editing program. Capabilities include: 
insert/delete, text compression /realignment, 
and buffer memory for saving portions of text to 
use elsewhere. Also includes tabulation, logi- 
cally formatted display, text save, and ZX/TS 
printer control. SASE for free information. 

Memotech 

Memotext 

EPROM: $49.95 plus $4.95. 

Brings commercial standards of text editing 
to your computer. Text is first arranged in 32 
character lines for the screen with comprehen- 
sive editing facilities. User chooses line length 
for printing and the system does the rest. Memo- 
tech printer interfaces enable output with 80 
character lines, upper and lower case, single 
and double size characters. On EPROM and 
plugs directly into your computer. 

Miscellaneous Programs 

John Richard Coffey 

Touch Type Game 

2K RAM. Listing: $1 plus long SASE. 

Learn to touch type all the ZX/TS symbols in 
a fun, challenging manner. Recommended only 
for users with special keyboards or overlays. 
Takes about 10 hours to master. All Basic. More 
detailed than the game that appeared in SYNC. 

Computer Software Associates 

Statistics Package 
IK RAM. $12.95. 

4 programs with error-correcting facilities to 
compute the following statistics: mean, standard 
deviation, variance, correlation coefficient, re- 
gression, equation, confidence interval for 
mean, 3 applications of the "t" test and the "F" 
test of the ratio between independent sample 
variances. 

Compuwtz Software 

The Educator 

16K RAM. Cassette: $10. 

A program to teach you all about program- 
ming your computer. All teaching is interactive 
and very easy to learn. 



July/August 1983* SYNC 



KDRizoq 

siMULdTinq 

TS/1000 

ZX-81 
OWNERS 



&*raagg 



zxs&m 



W^^B7^^^Tun^^NE^^TROCR«Ha 

FOR YOUR COMPUTER. 

EDUCATION 

GAMES ETC. _ 

TOR R FREE CflTPLOC RNO FREE 
PROGRAM LISTINGS, URITE- 
MORIZON SIMULATION 
789 S. GREEN BRY ROAD 



TIMEXSINCLAIR 

1000 




1983 Directory 



* Where to find: Disk Drives, RAM Extensions. Print- 
ers, Modems, Keyboards. Game & Serious Soft- 
ware, Books, Periodicals, Programming Aids, and 
other Exciting Accessories' 

* Articles on: Special applications like Control Cir- 

cuitry, EnhancedGraphics, Voce Generation, Music 
Synthesis. Video Inversion, Light Pens. Joysticks, 
etc 

* Complete Descriptions: Well tell you what it is, 

what it does, how much it costs, and where to 
buy it 

* Jam-packed w/photographs: We knew you'd 
want to see what these products look like So, we 
got pictures and put them inf 

Only $5.95 ... Postpaid! 

Sent First Class in the USA. 
To Order: Send check, money order, or VISA/MC 
number and expiration date MN residents add 6% 
sales tax. 

Dealer Inquiries Welcome. 

E. Arthur Brown Company 

Dept ZA-3 1702 Oak Knoll Drive 
Alexandria, MN 56308 Ph: 612/762-8647 



PREVENT 

erratic operation. A 
support designed for your 
Sinclair 16 K memory stops 
the white outs. The 
support mounts on your 
Sinclair ZX81.1000 case. 
Send for complete kit 

$4.75 POSTPAID 

Check or money order 

To 
THE FOURTH DESIGN 
PO. BOX 1406 
NIAGARA FALLS, N.Y. 14302 



Florida Creations 

Music /Sounds Package 
IK RAM. Listing: $3. 

5 programs and discussion for broadcasting 
music and spaceship noises to a nearby radio. 
No hardware modifications required. Controls 
the radio frequency interference generated by 
the computer. 

Home Applications 

Weight-Watcher 
Listing: $3. 

Basic program contains database of 200 foods 
and caloric values by portion with more than 30 
common activities to compute minimum daily 
requirements. Compare daily consumption as a 
dieting aid. Program can be tailored for personal 
diets or food preferences. Completely menu 
driven. 



Enjoying Your 
Computer: Games 

Miscellaneous Games 

B local Software 

(See Directory of Suppliers for prices.) 
Chase. IK RAM. 

Steer your interceptor to the target. Arrow 
buttons control velocity. 

Flower 

Display program plots ellipses in a spiral 
pattern. Watch as many varieties bloom. 

Fvee. IK RAM. 

A road racing game. Steer your formula car 
to a new distance record. 

Guess 

2 games in 1 . Hangman plus Guess the Animal. 
A self-learning game in which the computer 
questions you. 

Hollywood. Cassette only. 

As a movie produce you must obtain actors, 
script, and a director. Spending money begets 
money. 

Life 

Watch colonies of life-forms become alive, 
mutate, and die. Control matrix size, genera- 
tions. 

Meelborn. Cassette only. 

Two cars race toward a 1000 mile goal. In- 
cludes flat tires, accidents, running out of gas, 
stop lights. 

Pong. IK RAM. 

Two player pong game. Keeps score. 

Quicksand 

You are traveling through a forest and must 
detour through a swamp. Can you avoid the 
quicksand pits? 

Race. 2K RAM. 

A road race game. Can you break the distance 
record? 

Roadrace 

Steer a Formula-1 car through a tough road 
course. Different track each time. 



SyncMaster 

has the programs for 
your Timex-Sinclair 



1.VU-WRITE TEXT EDITOR 

. word processing simplilied • Perlect tool to 
document spreadsheets and programs , • Send 
letters, notes on cassettes • awaJaWe ^o 
add insert, delete, move text • Up to 348 lines 

01 32 cha 

2 DECISION MAKING 
. Sophisticated approach to computer-aided 
decision making, based on recent university 
research • Breaks down multiple problems into 
manageable sets, making decisions as you 
would 

3. DATA MASTER 16-64K 
. uses all memory available it needed* Keeps 
track ot any kind of data you want with custom 
searches, sorts and reports • Get what you need 
tram the computer, much easier than program- 
ming 

4. GRADE BOOK 

. Teachers cut a 3-hour t ob down to size 

■■..tes' Keep track of up^ 
with up to 30 grades per student * Un Hmi ed 
classes • Weight grades any way possible, us- 
ing your own formulae 
| 5. STAT MASTER 

. Written oy a statistics user for other users • 
Provides most useful descnpt.ve operations on 
your custom-designed data f«es- Variances. 
co-variance . standard deviation, standard lenror 
chi-square. hypothesis testing, confidence inter- 

neans. 
6. BUSINESS START-UP PAK #1 
• So you want to start a business' • Here are 
very uselui programs which provide information 
you will need to know but which most people g- 
nore • Break even with direct and variable costs. 
Sow much you need to sell to get your money 
back, help find true costs • Pay Back - should 
you buy that piece of equipment? Now it an 
easy question • How long will it take to make a 

7. FINANCIAL ANALYZER 

. Save big SSS on prepay-ng mortgage principal 
. What will your IRA be worth in he year 2000? 
. What was the real yield on that investment? • 
teres! rate calculations 

8 YEARLY DATEB00K 
• Never forget an important date again, i.e in- 
surance prem.ums due. anniversaries etc • 
List once a month tor all needed dates • 
Calculate day oi week from date 

9. INSURANCE RECORDS 
. Complete record -keeping ot household, 
business belongings, i e . jewelry, electronic 
eq Sment credit cards collectibles, everything 
• Use to help insurance agent recover alter a fire 
or burg 

10. SCREEN MACHINE 

input prompts anywhere on screen 

they belong • Complete error checking 

rormattinqand venl.cat.on • In MC for absolutely 

no screen flicker • Make your screen 100 /o 

neater and more professional • Commercial 

All programs require 16K 



Each Cassette *\ £} plus $1 postage 
Send $1 for Catalog 

S2 for any manual plus catalog; payment credited to first order. 



USE VISA or MC. call TOLL FBEE 
1/800/334-0854. Ext. 8«8 

| N NORTH CAROLINA CALL 

SyncMaster 

' 919/643-7120 
P0 p»vMl. 0akRMqe-NC-" 310 .l 



Were looking for programs in all fields. We 
will publish your programs, paying top 
royalties to you. if your programs are the best 
in their field and truly useful. 



July/August 1983* SYNC 



105 



SAVINGS x SAVINGS 

We are offering quality progrsas for 
the Tinex-Sinclsir 3rd ZX81 computers 
writteri in Canada and sold at 
Canadian prices* 

For the Canadian purchaser , there is 
no duty, Excise tax or currency 
exchange f 

For all other programmers, there is a 
savings of 202 or wore when you send 
a woney order in Canadian Currency* 
Send one dollar for our catalog of 
program and we will subtract that 
froM your first order* 

SOPHIA SYSTEMS 

15122 Pheasant Drive 
Surrey, 6*C. Canada, V3R 1X6 



TIMEX-SINCLAIR 



riCf*)OT€MT 



ZX81 TS1000 TS1500 TS2000 




Memocaic Spreadsheet (1 6-64 K) $48 95 

Memotext Word Processor (16-64 K). $48.95 

MemoAssembler(16-64K) $48.95 

TIMEX-Smclair'1500" Computer $74.95 

TIMEX-Smclair "2000" Color Computer 

16K . $148.95. 48K $194.95 

TIMEX-Sinclair 2040 Printer $89.95 

Seikosha 80 Char Printer Pkg $339.95 

(Incl Parallel Interfaces Cable) 
Memopak 1 6. 32. 64K RAM 

$48,95, $89.95, $138.95 
Basicare 4 Megabyte System Call or Write 

O-Save. Load/Save 6 Times Faster $38.95 

Memotech Keyboard $89.95 



To Ordmr Send check money order, or VISA/ 
irandexo date piusS2.00 shinning m 



. mn res add 6 J 
Writ* For Our Colorful Hmm Cmtmlog! 



£. Arthur Brown Company 

Division SM-3 1 702 Oak Knoll Drive 

Alexandria. MN 56308 Ph. 61 2/762-8847 



A REAL 
KEYBOARD 
FOR YOUR 

TIMEX-SINCLAIR. 

Full-size contoured keyboard 

Sturdy aluminum chassis 

48 sculptured keys 

No soldering 

$99* 

Permanent Sinclair-Timex legends on keys • 
Full-size advance bar (o>) • Individual keys 

tOr $ ; » EDIT DELETE • Shift lock • On- 

ott switch • Optional numeric keypad • Op- 
tional aluminum case that holds TS1000 and 

RAMpacks isnnnis 
nurnn 

INC. 

n9 Peter Si No 6 

Union City. NJ 07087 

(201)864-4410 

Send tor tree catalog Dealer inquiries invited 

Charge cards accepted. American Express Visa or 

KHPQK Mastercharge 

nurnn Union Clty NJ 07087 all nghts reserved 



Secrets 

Cryptographers. Code /decode messages with 
a keyword generated cipher. 

Shark -Hunt 

Chase a man-eating shark; trap it in your 
nets; avoid the rocks, old tires, and other snags. 

Snare 

Corral a wild stallion. Try to encircle him in 
the minimum number of moves. 

Tower. IK RAM. 

Guessing game. Code demonstrates poking 
the internal display file. 

War 

Inverse video graphics display program which 
plots a multiplayer card game. 

Worm 

Graphic display program. Plots a worm's path 
as it searches for entry into the ground. 



Computer Software Associates 

Towers Of Brahama 
IK RAM. $9.95. 

Challenges your skill and manipulation. There 
are 3 posts on the screen. Your starting base 
contains 5 disks stacked in ascending order by 
size. The remaining 2 are parking bases. To win 
this game, you must park the 5 disks on the third 
I post in an ascending order. 

Bulls and Co ws 
IK RAM. $9.95. 

A game of concentration for all ages! The 
computer randomly chooses 4 numbers. You 
must decipher the "master set" exactly. When 
you enter your guesses, the computer will tell 
you how many of the chosen numbers match 
the set, and how many match in exact order. 

Nim 

iurv i\Am. S9.95. 

The first player chooses a number of matches 
and arranges them in 3 piles. The second player 
then chooses a pile and removes some matches. 
The first player then removes some matches. 
Any number of matches may be removed from 
any pile. The winner is the person (or computer) 
who removes the very last match. 4 levels of 
difficulty. 

Four in a Row 
16K RAM. $14.95. 

A game for 2 or more players on a vertical 
board with 8 columns and 8 rows. The object is 
to get 4 pieces in a row: horizontally, vertically, 
or diagonally. Players alternate turns until a win 
is achieved. 

Slides and Ladders 
16K RAM. $14.95. 

Up to 4 players. Each player begins in the 
cellar of a mansion and must work his way 
through 40 rooms. The player to reach the 40th 
room first is the winner. 

Mugsy 

16K RAM. $9.95. 

You are the Boss of a Chicago gang operating 
a protection racket. Can you survive the rival 
gangs, the cops, and Nick the Greek? 



106 



Intercomputer Inc. 

Hopper (1017) 
16K RAM. $12.95. 

Can you help Fergy and his friends get across 
the highway and back to the lily pond? Includes 
crocodiles, logs, varying speed traffic, etc. 

Memory Master 

Code Master 

16K RAM. $10.95 pp. 

Menu allows 3 choices: 1 ) solve cryptoquotes 
stored in memory; 2) have the computer gener- 
ate a code from material typed in by the user; or 
3) solve a code from a newspaper, etc. Options 1 
and 2 offer 3 different types of code, each with a 
different level of difficulty. A cursor controlled 
control panel is used for letter replacement. 
Hint and quit routines make it easy enough for a 
10 year old to master but hard enough for the 
avid puzzle fan. 

MicroSync Software 

Air Traffic 

2K RAM. Cassette; $4 plus $1 s&h; listing: $2 

plus SASE. 

Try to dodge the oncoming planes and build- 
ings. Many levels of play. Keeps score. Fast 
action. 

Praise Data Systems 

Bible Quiz Games 

16K RAM. Cassette: $10.95 pp. 

A series of games to test your knowledge of 
Bible Scripture. Interesting and educational fun 
for the whole family. Keeps score for you so 
that you can see your progress as you play 
again. SASE for list of programs. 

SyncWare Co. 

Storm Lander 
16K RAM. $9.95. 

Make an emergency landing at Denver's 
Stapleton Airport in your commercial airliner, 
during a thunderstorm. Three screens of graph- 
ics show your progress in avoiding storm clouds. 
other aircraft, mountains, and downtown Den- 
ver, while homing in on navigation beams for a 
safe descent to the runway and finally taxiing to 
the terminal. 

Miner's Revenge 
16K RAM. $9.95. 

Get fabulously rich if you crack the mother- 
load. The old miner's last will, will help you on 
the way, equipped with a pick -axe, flares, spikes, 
and a lantern. The 9 markers left by the old 
miner will guide you to the big vein, but watch 
out for falls that cause the loss of time and tools. 
Not a text adventure game; continuous full 
screen graphics for improved realism. 

Super Slide 

16K RAM. $9.95. 

You are in the 1988 Olympics bobsled event. 
Pick up points while avoiding skid-patches, 
walls, ruts, and the course boundary. If you pass 
the qualifying run, you compete in two heats. 
Your score on both runs places your final posi- 
tion in a field of over 80 competitors. You must 
be very good to win the gold medal. Practice in 
the DEMO mode, which continually cycles a 
new course. Machine code action. 

Sikes Software 

Mega-tron 

16K RAM. Cassette: $14.95. 
Try to destroy the computer light cycle. Avoid 

July/August 1983 * SYNC 



hitting the light trails left behind the cycles, the 
walls of the game grid, and the cycles themselves. 
On screen scoring and bonus cycles. Machine 
Code. 

Skelly Computing 

Guess It 
16K RAM. Cassette: $3 plus $1 s&h; listing: $1 
plus SASE. 

A number game with 3 levels of play and 
prompting. 

2-Bit Software 

Working Mother s Dilemma 
2K RAM. Cassette: $14.95, 

Package of 4 games: Designed as a fun way 
for women to learn about computers: Mad Dash : 
Tests your ability to race through the house 
when you have not had a break all day. Carfool: 
Figure out how to use the least amount of gas 
while running errands all over town. Harried 
Housewife: Adventure game that rewards you 
with a hot bath and a nap after a hectic day that 
includes a dazed search for your car in the 
parking lot of Shopping Mall. 

Shoot em Up Games 

Blocal Software 

(See Directory of Suppliers for prices.) 
6-Shooter 

A game of skill in which you try to hit a 
randomly moving target. 5 levels of difficulty. 

Artillery 

Protect your hometown from enemy planes. 
Variable gun angles, limited ammo, so aim care- 
fully. 

Bomber 

Maneuver your bomber through anti-aircraft 
flak to drop your payload over the target; fuel 
limit. 

Dogfight 

Shoot down the enemy planes before they 
destroy your 5 planes. Fuel and ammo limits. 

Sniper. IK RAM. 

A randomly moving target pops in and out of 
view. Hit it before it disappears. 

Wolfpack 

You are the commander of a Navy destroyer 
searching for enemy submarines. Depth charges 
ready. 

Computer Software Associates 

Murgatroyds Revenge 
16K RAM. $14.95. 

The fiendish Murgatroyds are on the warpath 
again ! You must fight off their attack with mines, 
superglue, decoys and more. 

Robot Tanks 
16K RAM. $14.95. 

The battle has gone poorly. Enemy tanks 
have you surrounded with an unlimited supply 
of ammunition. You have one shot left. After 
you have fired your final round, your tank will 
become immobile. Your only source of defense 
is to lure your enemies into shooting one 
another. Good luck ! Save your last shot to win ! 



July/August 1 983 c SYNC 



MicroSync Software 

Bomber 

2K RAM. Cassette: $3 plus $1 s&h, listing: $1 

plus SASE. 

A target practice game in which you try to hit 
a target on the bottom of the screen. 2 types of 
missiles, one bomb. Target explodes when hit. 

Robert J. Midura 

Strategy at Sea 

16K RAM. Cassette: $10. 

2 games. Convoy : Shooting gallery type game ; 
your sub has 20 missiles to attack a 15 ship 
convoy ; targets pass in either direction at various 
distances from your sub; graphic explosions; 5 
levels of play; 5 types of ships; score shows all 
ships sunk. Sub Hunt: Your destroyer must 
track down and sink 5 nearly invisible subs 
before they sink your 5 fleet ships or your 
destoyer; watch out for mines and collisions 
with your own ships; graphics display of ocean 
grid, fleet ships, mines, depth charges, and ex- 
plosions. 

Space Games 

Biocal Software 

(See Directory of Suppliers for prices. ) 
Cruiser 

Navigate your spaceship through a meteor 
storm . How far can you travel without damage? 

Orbit 

Maneuver your spaceship into an inner orbit 
to pick up your cargo. 

Treasure 

Collect the treasure before the alien robot 
catches you with its radar tracking system. 

Computer Software Associates 

Galactic Patrol 
16K RAM. $14.95. 

Your 6 year mission is to explore new worlds, 
to go where no being has gone before ! Your job, 
as captain of the Galactic, is to protect the lives 
of the 500 aboard and to operate the bridge. 

Super Invaders 
16K RAM. $14.95. 

Negotiations have ended. Now comes a show 
of strength. 'The Earth is being invaded!" All 
beings on Earth are depending on you. Don't let 
us down! 

Intercomputer Inc. 

Arcade Games (FG1016) 
16KRAM. $12.95. 

In any other time or galaxy, the dust ball of 
the world called Tai would have been quite 
unimportant. Time changes and the entire civ- 
ilization will be betrayed. You have been chosen 
to defend Tai. The galactic future depends on 
you. 

Memory Master 

Spacefhsh 

16K RAM. $10.95 pp. 

Earn shots at an alien landing craft by suc- 
cessfully answering questions in various drills. 3 
levels of drill in addition, subtraction, multipli- 
cation, division, and visual memory training. 
Complete scoring for drills and space game. 
The visual memory drill automatically increases 
in difficulty as the player gives correct 
responses. 



Tactile Feedback Overlay 

Port ZX 80/81, TIbsx 1000, or Hlcroace 
— TOUCH TYPING POSSIBLE 
** STOP KISSED KEYS 

•• SPEED ENTERING PROGRAMS 

With our easy to Install keyboard overlay 

♦ 3.95 



1?K Softyarefor Z^TifWMQQQ 



ZX FROGGIE An excellent version of the 
arcade ftere. Fro^le rust cross the busy 
highway and hop the logs to get ho»e. Pull 
screen novlng graphics, fast a/c action, 4 
levels, different screens and speeds. Naae 

and SAVE three best scores. $1^.50 

D RAGON H UN T A naze game played In Dragon 
Caves. You »ust find * slay } dragons. There 
are 15 arrows and a aagic sword to help you 

survive the hidden dangers. $12.50 

WORD SING A word processor for the Sinclair 
or other 32 ool . printer. Past m/c Inserts 
variables, lists, moves and Justifies. 9000 
characters with l6K, Is easily expandable. 
Menu controlled. With Instructions.- 1*12.50 
Pour l6K Programs on One Cassette 

HATH TUTOR Add .subtract. multiply * divide. 
Five levels in each. Menu controlled. 

TYPING SKILLS A fun and competitive skill 
Improver. Set speed, keep up to the computer 

BIRDS Guide missiles to Intercept the Bird 
or what it drops will bring a nasty end. 

ASTRO SMASHER Dodge asteroids, smash enemy 
ships before force shields fall. — 1 12. 50 
U.S. Orders toi P.Hargrave, Site V, RR k, 
Nanalmo. B.C., Canada V9R 5X9 



SERIOUS PROGRAMMERS 

"MUST-HAVE" UTILITIES 
For ZX-81 and TVS 1000 Computers 

FILE*SYS $10 

Read/Write Cassette Data Tape Files 
(fast, flexible, reliable) 

FILE'BASIC $15 

Save/Merge/Erase BASIC Segments 
(includes FILE*SYS functions) 

FILE*VARS $5 

Save/Restore Strings & Arrays 

(requires FILE-SYS or FILE'BASIC) 

BASIOOLAY $10 

Overlay/Copy BASIC Segments 



►rrrwts full 






,plc 



tlterfde r via HSU fun. ttOfl 
Well- dnrumfnte d user m <iini.il-. 
Available* oniapr rdssnir in t %•!<.. .11.1 Mp mat hint- Idng 



SASE for Info 



i 



( tii'i k or MO delivers mm 



OinusWare 

6 Turning Mill Road 
Lexington, MA 02173 



M P S Y 

(Matrix Operations Programming 
System) 

The power of linear algebra 
at your finger tips. Specially 
designed for college students, 
scientists and professionals. 
Multiple applications to solve 
systems of equations , polyno- 
mial interpolations, statisti- 
cal analysis, heat transfer , 
electrical circuit analysis f 
animal population studies and 
more , 

Program cassette, users and 
appl icat ions manual . 

Send $2 5 check or money 
order to: 

MOPSY 
P.O. Box 196 
Glen Oaks, New York 11004 

(N.Y. res, add $2 sales tax) 



107 



MEMOSHA 




MEMOSHA: Allows the Sei- 
kosha and Radio Shack printers 
to list the entire ZX-TS 
character and graphic set using 
the Me mo tech Interface 

• Titled and page numbered 
listings 

• Works with new as well as 
saved program 

• Line remembering routine 
included ($15.95) 



VOXCOMP: Computer generated speech with 
resident vocabulary permitting unlimited phras 
and sentences; allows the TS1000 to vocalize 
instructions, answers, and messages - which can be 
integrated into your programs (requires PARROT 
Speech Synthesizer by R.I.ST Inc. ) ($15.95) 

SPECTREX: Creates true perspective drawings 
from user defined data points; viewing angles may 
be changed at will; data is entered only once and is 
maintained by resident file manager ($15.95) 

FINANCIAL MANAGER 1000; A completely 
integrated business-home budget, expense, checking 
and financial management system. Maintains 
monthly and year-to-date records of 35 user defined 
categories ($15.95) 



INNOVATION CAN BE 

Ft N -ENQUIRE ABOUT 

OTHER SYBER 

SOFTWARE 



_WS4_ 



SYBER 

1325 Oilier Rd 
Ocean Springs. MS 

39564 
Phone:601-875-3682 



' ^■*- + >^+++** 0* m *+***-*0**********> +* -*-*+* +*^+ **+***>*0**^^ 



INSTANT LOADING! 
A MUST FOR 



7VR1 



tr 1 nnn 



OWNERS 
1K-64K 

EM* to um 8K EPROK PROGRAMMER. Housed In t si in He flat cab*, 
with ribbon connector and expansion slot for RAM packs ttc . Uses 



two UK 2732 EPROMS in tha 8-16K aamory Blot. It corns s completely 
, aaeembled with instructions and software ao you can load the EPROMS 

with BASIC and/or Machine Code . Has zero insertion force sockets 

so changing programs is as easy as cassettes. Load these programa 
, into RAM in less than a second . Result. Programs that fail-safe 
| load almost instantly. With one <* EPRQM, $64.95 plus $3-00 ship- 

ing and handling. Additional EPROMS, $4.95 ("A residents please add | 



sales tax) . 



<»— > #■#■< 



**^ + + ^ *+ ~+ ^m+^^^^*^^+^ + + +^ ^^+ m + m +^ m 4 m +^ m + m + l ^ ^ + t ^ l + J 



MAV M I CROPRODUCTS 

BOX 31256 
SEATTLE WA 98103 



ARE YOU HAVING PROBLEMS 
UNDERSTANDING THE MANUAL? 



No problem. Understanding Sinclair Basic 
is a newly developed learning aid which 
displays and demonstrates 54 Sinclair 
Basic commands. Basic program lines are 
displayed and simultaneously run on a 
split screen. Go as fast or slow as you like 
because the program waits at each line 
for your cue to continue. Repeat each 
program as often as you like by pressing a 
key. Written in machine language and 
basic, Understanding Sinclair Basic gives 
you a powerful tool with which you can 
unlock the mysteries of Basic program- 
ming. 16K required. 

$15. PLUS ONE DOLLAR FOR POSTAGE/ HANDLING. 
NEW YORK STATE RESIDENTS ADD 8% SALES TAX. 
SEND CHECK OR MONEY ORDER TO A. + ASSOCIATES, 
175 FIFTH AVE., SUITE 3119, NYC WOW 



A. ^Associates 




<&ip 



Z.S.S. SINCLAIR 
COLD SHUTDOWN. 



You are a member of the Zoological Survey Ship Sinclair. So far you 
have had a very sucessful mission, you collected many specimens on 
many strange worlds. Many dangerous specimens. It was time to go 
home. Everything went fine, coordinates were set, computer activated 
and you along with the rest of the crew entered the Stasispod for a long 
sleep. Two months later the ship encountered an intense electro- 
magnetic pulse. You awaken not to find yourself in orbit above Earth, 
but in deep space. The life support units of the other crew members 
have malfunctioned. But you are not alone, the specimens are loose! 
Awakening earlier than planned, you are left weakened and 
disoriented. The ship is laid out in the form of three wings composed of 
modular units called Pods. Funny thing, but you can't remember where 
any of them are located. The creatures have managed to scatter the 
equipment you need to help you survive and repair the ship. The reac- 
tor is getting cold and you have to repair the five major Pods 
(COMPUTERPOD, C0NTR0LP0D, NAVIGATIONPOD, FUSIONPOD, 
LIFESUPPORTPOD), before it goes into COLD SHUTDOWN... 

• VERY USER FRIENDLY • 33 PODS RANDOMLY PLACED 

• EVERY GAME DIFFERENT * OVER THIRTY CREATURES 

• EIGHT TOOLS AND DROIDS • 30 mln - 1 hr. PLAYING TIME 

• GRAPHIC DISPLAY OF SHIP, YOUR POSITION, SYSTEM STATUS 

• TWO WAYS TO WIN: RESTART SHIP OR TAKE OFF ON 
ESCAPECRAFT PHOENIX 

8k ROM 16k RAM Supplied on cassette with instructions. 
$12.95 postpaid Money Order or Check Made Payable to: 

T.H. McCOMB. 

THMSOFTWARE 154 Laconia Avenue, Staten Island, New York 10305 



L 



• * DEALERS ENQUIRIES INVITED* • 




CHIRPER module for your ZX81 
or your tlmex/sinclalr 1000. 

The CHIRPER module lets you enter key- 
board data fast and accurately. A sound can 
be heard when a key is entered enabling you 
to spot a missed entry or a double entry with- 
out looking up at the screen. A buzzy-chirp is 
produced when the key entry routine runs on 
a 1 or a 2K machine. A large program in a RAM 
pack produces a continuous tone that changes 
on key entry. 

A program can control the sound. Included 
is a demo program that converts the keys into 
a music keyboard of over two octaves. 

The CHIRPER module installs easily inside 
the ZX8 1 case with only three wires to connect. 
Complete installation instructions are included. 

To order your CHIRPER send a check or 
money order. We pay postage in the USA or 
Canada. 

&EJJH)n®©IMIPIKI (S®o 

3584 Leroy. Ann Arbor. Ml 48103 



MOTION PLATFORM 

for 

ZX81 and TS1000 




* Computer not included 

• Program your ZX81 or 
TS1000 to make it move 
in any direction 

• Battery powered 

• No internal modifications 
to your computer 

• Sample programs and 
documentation included 

• Useful for robot projects 

• Only $299* 

Make check or money order payable to: 

BINGEL ROBOTICS 
3540-244 SW ARCHER RD 
GAINESVILLE, FL 32608 

Please include $3.50 shipping/handling 
F L Residents add 5% Sales Tax 

* Computer not included 



Tarbon s Revenge 
16K RAM. $10.95 pp. 

An enhanced version of Spaceflash. Position 
your space ship to intercept the alien with one 
of your missiles. Select the number of ships that 
must be shot down to win and the number of 
ships Tarbon must land to conquer the earth. 
As your aim gets better, Tarbon makes it more 
difficult by sending down smaller ships. 

MicroSync Software 

Galaxy Master 

IK RAM. Cassette: $4 plus $1 s&h. 

Fight the aliens on the top; watch out for the 
bombs that they drop. 3 levels of play. Machine 
code. 

Slkes Software 

Moon Mission 

16K RAM. Cassette: $14.95. 

Land your space craft safely on one of the 4 
launch pads. Features: Full graphics display of 
mountain terrain, launch pads, and lunar cities. 
Instrument panel assists you in landing safely. 
Machine code. 

In vaders 

16K RAM. Cassette: $12.95. 

Shoot down the marching aliens with your 
rapid fire laser cannon before they take over 
the planet forever. Shields are provided for 
protection against the aliens' bombs. Machine 
code. 

Casino Games 

Biocal Software 

(See Directory of Suppliers for prices.) 
Blackjack 

Multi-player, multi-deck version of popular 
21 card game. Sharpen your skills for Las Vegas/ 
Reno. 

Bong 

Throw dice until you reach 10,000 points. Is 
and 5 s are scoring dice. Up to 5 players. 

Craps 

Bet on the dice rolls. Up to 5 people. 

Solitaire 

Las Vegas version. Standout layout is dealt 
with remaining deck dealt face up over last 6 
columns. 

Compuwiz Software 

Casino Fun 

16K RAM. Cassette: $10. 

This very comprehensive Blackjack game fol- 
lows full casino rules such as double down, split 
a hand, etc. Hi-lo is derived from the popular 
English game. Excellent graphic displays are 
used in both games. Watch the "chips" go up 
and down as your winnings fluctuate! 

Casino Fun II 

loK RAM. Cassette: $10. 

Play the exciting game of Baccarat as it is 
played in European casinos. Graphics display 
of cards, messages, and chips. Memory chal- 
lenges and develops your ability to recollect. 
For all ages. 



TECHNI-STOCK SOFTWARE SYSTEM 
HIGH PERFORMANCE SOFTWARE 

for your ZX81/TS1 000 

6 reasons why TECHNI-STOCK SOfTWARE SYSTEM out 
performs all other Technical Stock Analysis Programs. 

1) Detailed price-volume charts on Logarithmic Grid 

2) Sophisticated Statistical Analysis wKh Stock and Market 
comparisons 

3) Technical evaluations based on risk, return, moving aver- 
ages and price momentum indicators 

4) Handsome binder with detailed instruction guide and 
evaluation manual 

5) Personalized Stock Data worksheets for your favorite 6 
stocks and a market average 

6) Unique system for preserving analysis evaluation in your 
Techni-Stock binder 

*frjr use with 16K or more 

TO ORDER YOUR OWN TECHNI-STOCK SOFTWARE 

SYSTEM just: 

1. Fill in your name and address 

2. Fill in the names of your favorite 6 stocks 

3. Clip this coupon and mail to us 

* Sorry no refund. However defective cassettes will be 
replaced. 

GENTLEMEN. PLEASE RUSH ME YOUR TECHNI-STOCK 
SOFTWARE SYSTEM for only $34.95 plus $3 00 shipping 
and handling TO: 
Name 
Street 

City Zip 

Indiana Residents Add 5% Sales Tax 
Stock #1 
Stock 12 
Stock #3 
Stock #4 
Stock #5 
Stock #6 
ENCLOSED IS A DCHECK OR JUSTCHARGE MY: 

□ VISA □ MASTERCARD 

Acct No 

Exp. Date 

Signature 

MAILTHISC0UP0NT0 

TOCO TECHNOLOGY 

P BOX 98 
SANTA CLAUS. INDIANA 47579 



EC0-L0GIC 

SIMULATION 




THE DESPERATE 

herd roams a hot tor- 
rid plain, grazing on 
the patchy brush, always seeking more until they 
find it or starve . , . reproducing if only they can 
eat enough. The rains come bringing thick 
vegetation, but the herd's gluttony leads to a pop- 
ulation explosion— then famine, and the beasts 
starve in droves, 

YOU control metabolism and energy require- 
ments of the beasts and growth and food value 
of the vegetation. 

FAST ANIMATION by machine code and 
RPNZL™ makes for nonstop on-screen action. 
Beast in the Field TS1000 16K $14.95 

METEOR STORM'S fast arcade-style anima- 
tion graphics bring the TS1000 the excitement 
you thought you'd never see. Challenge yourself 
to command your craft through a storm of inter- 
stellar debris-your skills as pilot and gunner 
will be stretched to their limits. 
Meteor Storm TS1000 16K $7.95 
Add $.50/tape p&h. CA residents add sales tax. 
FREE catalog on request. 

THE GOLDEN STAIR 

141A Dore Street, San Francisco, CA 94103 

(415) 552-1415 



July/August 1983 c SYNC 



109 




L&G Car-Comp Power Flat 

• Use your TimexSinclair in your car 

• Only 12V lighter outlet needed 

• Permanent housing for computer/cassette 

• Steady voltage prevents overheating 
Vu-Load Monitor 

• Insures program load 
Level-Vu Prism 

• For easy tape counter reading 

Car-Comp 59 95 + 3.00 P H 
Vu-Load 20.95 + 2.50 P H 
Level-Vu 2.95 + 1.00 P H 
L& G Enterprises 
Box 6B54 
Silver Spring. Md 20906-0854 
301-774-0126 



(16K) ZX-81/TS-10OO SOFTWARE 
YOUR KEY COLORS USING NUMEROLOGY 
Each individual is unique! Learn by graphic 
display-colors you emanate and character- 
istic meanings. 

SYNC INDEX (Menu driven) 
Spending hrs looking for an article in one of 
those back issues? Program provides index 
data for past 2 years. Search by 1 of 12 
categories or by keyword. Displays subject, 
volume date and page number. 

HOUSEHOLD BOOKKEEPER (menu driven) 
Enter the date. Displays all bills due for that 
week Up to 16 bills are graph displayed by 
quarter selected. Maintains summary of 
expenses paid, average cost, and expense as 
percent of income. 

Printer opt. all prog. Sp.ZX or P40 Cassette 
$9.95 ea. (incl. post.) Ca tax. SASE for more 
information. 

I. M.S. ENTERPRISES 
Box 4503 
Lancaster, Ca, 93539 




CATALOG! 



Just let us know and we'll mail 
you a FREE Creative Comput- 
ing Catalog- 16 pages filled 
with books, buyer's guides, 
magazines, and more! 

To get your FREE catalog, 
write to: Creative Computing 
Catalog, Dept.NEBF 39 East 
Hanover Ave., Morris Plains, 
N] 07950. 



Slkes Software 

Blackjack 

16K RAM. Cassette: $9.95. 

Casino blackjack at its best. Take your $500 
bankroll and put your luck to the test. Full 
graphics display of cards makes this game fun 
and exciting. 

Maze Games 

Biocal Software 

(See Directory of Suppliers for prices.) 
Amazing 

Can the mouse reach the cheese before that 
cat catches it? Watch the mouse travel through 
the maze. 

Catnmouse 

Two cats chase a mouse through a maze. You 
control the mouse to score on its way to the 
cheese. 

Maze. IK RAM. 

Shifting maze. Prints random maze. 

Computer Software Associates 

Mazeman 

16K RAM. $14.95. 

Mazeman scours the maze for food while 
dodging ghosts which are trying to devour him. 
Are you capable of beating the high score before 
Mazeman is devoured? 

Sikes Software 

Micromaze 

16K RAM. Cassette: $16.95. 

Eat the dots and score points while evading 
the deadly Drone; 1 1 automated levels of play, 
so the better you play, the better this game gets. 
Almost unbeatable. Machine code. 

Other Games on the 
Computer 



(See Directory of Suppliers for prices.) 
3DTTT, Cassette only. 

Challenge the computer in a game of Tic- 
Tac-Toe. Played in 3 dimensions on a 4 by 4 by 4 
grid. 

8-Ball 

Call your stroke, cue-angle, and object ball 
angle. The computer calculates all subsequent 
angles. 

BCKGMN 

Challenge the computer, play against another 
player, or watch the computer play both sides. 

Checkers 

Challenge the computer to a game; includes 
demo game and two player mode. 

Cube-Sym 

Rubik's cube simulator. Use any size cube. 
How many moves will you take to solve it? With 
scramble. 

Stuart Software 

Pick em 

16K RAM. Cassette: $14.95 plus $2 s&h. 

Predicts the outcome of NFL games with point 
spread. 



NBA Picks 

16K RAM. Cassette: $14.95 plus $2 s&h. 

Predicts the outcome of NBA games with 
point spread. 

SyncWare Co 

NFLX Football 
16K RAM. $9.95. 

Provides a full -featured football contest for 
one or two players. Not a "text" game. Safeties, 
interceptions, runs, passes, punts, fumbles, and 
field goals are displayed with machine code 
graphics. Defensive plays include Blitz, Red 
Dog, Normal, and Prevent. Includes demo 
option to continually demonstrate pass and 
running plays. 

Game Collections 

Charles J.Bonner 

Flight Simulations 

2K RAM. Cassette: $12.95. 

4 flight programs; some with graphics. Guide 
a parachute to a target; fly a biplane over a 
mountain range; fly a jet airliner across the 
Pacific Ocean ; navigate a spaceship from the 
Asteroid Belt to Earth orbit. 

Computer Software Associates 

IK Games. $19.95. 

5 games: Duck Shoot: All the excitement of 
duck hunting, without getting up at 4 a.m. Moon 
Lander: If you thought Neil Armstrong had it 
easy, this is your turn to try to land on the 
Moon. Hangman: 1 or 2 players; sharpen your 
spelling skills. Crossword: Challenging, mind- 
boggling word association. Letter Square: Ar- 
range the alphabet in correct order. 

Compuwiz Software 

Arcade Fun 

16K RAM. Cassette: $10. 

3 games: Arcade type; moving graphics. 
Escape: Get as many points as possible before 
the closing walls crush you. Snake: Devour 

pCintS. lesvin" 2 trsil over whi^h von rannnf 

cross. Trap: Two players are set against each 
other. 

2K Game Pack 

2K RAM. Cassette: $10. 

5 programs : Kaleidoscope : Dazzles you with 
super displays. Over Under and Remember: 
Two challenging and thought provoking card 
games. Reverse: Explore your skills in logical 
thinking. Sketch: Let your imagination run wild 
and become an artist. 

Mind Benders 

16K RAM. Cassette: $10. 

3 thinking games: Master Mind: An exciting 
version of the popular board game. Super Mind : 
A tougher version for those who enjoy a real 
challenge. Guess: An enjoyable number guess- 
ing game. All games use full screen graphics. 

Florida Creations 

Fun and Games Package 

IK RAM. Listing: $1 plus SASE. 

2K RAM. Cassette: $9.95 plus $1 s&h. 

3 programs: Draw : Draw and sketch whatever 
you want; automatic erase; flashing cursor. 
Lunar Lander: Land you LEM on the landing 
pad without blowing up; horizontal and vertical 
velocities; fuel. Secret Code: Converts your 
messages into an unintelligible string of alpha- 
numeric characters and back into English. 



110 



July/August 1983 z SYNC 



NO MORE BAD CASSETTE LOADS 

with 

THEZDUBBER 

The frustration of trying to load a cassette program into your Sinclair 
XXS< ) 8 1 or Timex KKM). is this what you really bought your computer 
for ; Why put up with it? Now you don't have to. The Z Dubber is a 
small device which connects between your computer and cassette 
player, improving your loading ease !(>< 




The Z-Dubber also allows you to connect two tape recorders togeth 
er, to create perfect duplicates of your favorite cassette programs. The 
Z-Dubber can be yours for $31.95 postage paid within the U.S. area. 
Money back guarantee if not satisfied. Visa & Mastercard welcome. 

BYTESIZE MICRO TECHNOLOGY 

PO BOX 21123 -SEATTLE WA 98111 

206-236-BYTE 



WE HAVE WAYS 

OF MAKING YOUR 

ZX81 TALK 

THE ZXTALKER 

■ UNLIMITED VOCABULARY 
•VARIABLE FREQUENCY 

■ SPEAKER & 500mW AMP INCLUDED 

• INCLUDES SAMPLE SOFTWARE 

• $99.95 

THE ZXPANDER 

• USE 3 PERIPHERALS AT ONCE 

• REDUCES WOBBLE $2495 



CALL 1-408-2484516 rem OOCHSTTUT I CM 
KM) CHECK C* KMI C4BCK OM KASE F0» SPECS. 
CA. RESIDENTS ADO tfruCULI SALES TU 



USER FRIENDLV RE5ERRCH 

478 W. HAMILTON AVE SUITE 154 

CAMPBELL, CALIFORNIA 95008 

INCLUDE 5\ FOR POTTAGE. CITTU REFUNDED 



SOUND with SINCLAIR 



MAKE AMAZING SOUND EFFECTS 
WITH YOUR ZX 81, TIMEX 
Sinclair 1000 or SPECTRUM 

THEZONX8l!f9.95 




• * 



ft 

r 



&& 



p&pe 

» The ZONX SOUND UNIT is completely self contained and especially 
designed tor use with the ZX 81, TIMEX Sinclair 1000 and Spectrum 
Computers It |ust plugs in - - no dismantling or soldering 

• No power pack batteries, leads or other extras * 

• Manual Volume Control on panel ample volume trom built m loud 
speakei 

Standard Sinclair - 1 6K Rampack or printer can be plugged into ZONX 
Sound Unit without affecting normal computer operation 

• Huge range ot possible sounds tor Games Mush Helicopters, Sci-Fi 
Space Invaders Explosions Gun-shots Drums. Planes Lasers Or 
gans Bells Tunes Chords, etc or whatever you 

• 8 tull octaves Uses 3-Channei sound chip giving programme control ot 
pitch volume ot tones and noise all with envelope control 

• Easily added to existing games or programs using 
BASIC lines or machine code 

• No memory addresses used I O map) 

FULL instructions with many examples ot how to obtain effects and 
the programmes, supplied Fully guaranteed. British Hade. 

• Except with Spectrum you need the Spectrum t xtensiort Board Order 
No SEl PRICE $10.95 inc. 

Payment may be made by Cheque P O 
Giro No 388 7006 Postal Order or Credit 
Card 

Export orders Bank Cheque Interna 
Money Order US *Or£ St© 





ZX-MAN 

Turn your ZX8I or TIMEX 
SINCLAIR 1000 into an ar- 
cade type game computer with 
ZX-MAN. 100% machine 
code makes this fast acting pro- 
gram as much fun as being at 
the arcades. With the joystick 
option you can have the real 
feel of game playing never be- 
fore available for your ZX8I 
or TIMEX SINCLAIR 1000. 
1 6K required $14.95 



JOYSTICK and ZX-MAN-Both for $24.95 



JOYSTICK 
With ATTO-SOFT's JOY 
STICK your ZX8 1 or TIMEX 

1000 can be turned into an ar- 
cade type computer allowing fast 
control over ZX-MAN and other 
type software. Requiring only six 
simple solder connections inside 
your computer. Also included is 
software to develop your own 
programs $ 1 4.95 

Send Check or Money Order to: 



flTra-SQrT 




American 

Express 

Accepted 



832 E. Third Street 

Galesburg, Illinois 61401 

(309)343-41 14 



Please add S3.50 
Postage and Handling 
COD $2.00 additional 



TEACHERS GRADEBOOK (32K) 

- START THE NEW TERM RIGHT - 
TRACK 40 STUDENTS/ 40 EXAMS TESTS. 
QUIZZES. QUARTERLIES AVERAGED AND 
WEIGHTED. TRACK HOMEWORKS & PERFOR 
MANCE FACTOR ADD /DELETE, ALPHABET 
IZING. SUGGESTED REPORT CARD GRADES 
REVIEW STUDENT' CLASS RECORD. PRINTER 
OUTPUT. FULL SUPPORT, ♦ MORE SELF 
START /SELF SAVE/ SELF NAME $24 95 
MARKEL SOFTWARE /P OB 2392 SECAUCUS 
N J 07094 



*•* UNBEATABLE SOFTWARE OFFER •" 

3 QUALITY CASSETTES FOR $12 + $2 S&H!!! 
Included in these cassettes are BLACKJACK, MAS- 
TERMIND, ESCAPE and 5 more games. All games use 
excellent displays and run very fast. Send $14.00 to: 

COMPUWIZ SOFTWARE 

PO Box 390078, Mt View, CA 94039 

ORDER NOW!! SASE and get FREE MC program! 



FREE 



CATALOGUE OF 90 PROGRAMS 
-BIOGRAPH SEND BIRTHDATE 



OH CASSETTE: STOCK OPTIONS $ 7.95 

REAL ESTATE PLANNING $12.95 
DAS BOX612 HADDONTIELD,N.J.080 3 3 



*********************************** 

* ! I ! ! Excellence in Performance!!!!* 
*********************************** 

* H Cosmic Galaxian Arcade" ZX81/TS * 

*Dennis A. Donovan IK ram * 

*3125 Park Avenue Suite 11B * 

*Bronx r New York 104 51 * 

* Check or Money Order Payable to * 

*Name Above...... $1.00 Listing. * 

*********************************** 



r 



IMPROVED HEAT SINK for ZX81 & 
TS1000 eliminates system crashes 
caused by overheating. $7.95 
check/money order or SASE for 
complete details to: 
BASCO, 289 Baxter La, Milford 
CT 06460 



Sinclair computers We share information, pub- 
lish a newsletter and have a cooperative for com- 
puter products which are discounted Join us 



SINCLAIR USERS' NETWORK 
2170 OAK BROOK CIRCLE 
PALATINE IL 60067 



/ 



312 934 9375 



STARTER PACKAGE 

ZX/TS(1K) 

This is a group of 14 programs to introduce the Ian- 
gauge baste. These programs cover several topics 
(games, education & graphics) only $14 

Troiano Software Company 

P.O. Box 40 

Nesconset. New York 1 1767 



AC CKT ANALYSIS FOR ZX81/TIMEX 
1000 COMPUTE CKT FREQ RESPONSE 
OF OP AMPS, TRANSISTORS, FETS, 
RLCS, TRANS LINES, OP/SHT STUBS, 
REQS 16K MEMORY. INST & CASSETTE: 
$9.95 PLUS $1 S&H PER ORDER. 

Computer Electronics Division 

P.O. Box 1332 
1 mMNNTL Monterey Park, California 91754 



□ 



"FLIGHT-PLANNER" for PILOTS 

—maintains database of airports & VORs 

—computes distance and true course 

— corrects-course for wind and computes best altitude 

of flight 

—generates enroute VOR checkpoints like RNAV 

waypoints 
— performs weight and balance 
Send $10.00 to Joe Smiley, 
8A Anthony Circle. Newark. DE 19702 






1 I 



SyncWare Co. 

Fun and Games I 
2K RAM. $9.95. 

5 games: Bring those TS 1000s out of the 
closet. Included are Syncwars, Minotaur, Nim, 
ContsEntration, and TS Doodle, combining 2 
older Basic games with 3 new ones in a "some- 
thing-for-everyone" package. 

ZXSystems Software 

ZX-Pack 

1K-16K RAM. Cassette: $16.99 plus $1.50s&h. 

9 games and programs: Ranging from 4Dict- 
tactoe to ZX-Probe and a savings account bal- 
ance computing program. Instructions. 

Horse Racing 

CRC Software 

Horse Master 

16K RAM. Cassette: $12.95. 

Before you go to the track... consult with the 
Horse Master! Your racing form or local news- 
paper gives you the date, and this program will 
help you analyze it! 

A. Doty 

Horse Racing Handicapping 
16K RAM. Cassette: $12.50 pp. 

Analyses thoroughbred races giving critical 
handicapping parameters for each horse. Based 
upon statistical methods by using key past per- 
formance information to aid in predicting po- 
tential winners. Instruction pamphlet. 

M. H. Marks Enterprises 

Handicapper 

16K RAM. Cassette: $9.95. 

This program will help the horse racing fan 
make more intelligent decisions at the wagering 
window. After pertinent data obtained from 
standard racing programs is entered, the com- 
puter assigns appropriate "points'' to each par- 
ameter based on a wpiohtpri «vQt pTn and 3 display 

of the percentage of "chance to win" of each 
horse in the field. 

3G Company, Inc. 

Horse Race Handicapping Program 
16K RAM. Cassette: $24.95. 

This is a scientifically derived system for 
calculating odds on horse racs. Hundreds of 
races were analyzed and numerical probabilities 
computed to form the basis of this program. 

UAS 

Flat Racing. (C6001). 

16K RAM. Cassette: $12.95. 

Handicap the thorobred horses on any track. 
Input data from the facing form and find the 
racing form and find the potential winner. The 
program follows the proven concepts used by 
the Win-rator to find the most probable winner. 

Hangman 

American Micro Products, Inc. 

Hangman 

16K RAM. Cassette: $17.95. 

A computerized version of the classic 
children's game of Hangman. Preprogrammed 
with 235 words; however, the user can replace 
these with more than 500 words. 



Computer Software Associates 

Lynchmob 

16K RAM. $12.95. 

A competitive game of skill and strategy for 
2-6 players developed from the traditional game 
of Hangman. Picks turns, keeps scores, and 
lynches the losers in animated graphics. 

Gladstone 

Hangman (Z78) 

16K RAM. Cassette: $9.95. 

2 games. Movies: Over 100 titles and film 
stars; 3 categories. Superheroes: Names and 
their arch-enemies. 

Ha\ market Software 

Havmarket Hangman 
16K RAM. Cassette: $9.95. 

5 categories with instructions on how to 
change the category names to suit individual 
needs. Each category contains up to 50 words 
and the computer even adds the words you use 
when playing with two players. In effect, the 
computer learns. Increase your children's vo- 
cabularies or just put in their spelling list. 

R. Midura 

Hangman 

16K RAM. Cassette: $10. 

Features a graphics display, a scratch sheet 
display to keep track of letters guessed, 7 word 
categories, score keeping, and 400 word 
dictionary (prerecorded dictionary: animals, 
vegetables/fruits/herbs, music, astronomy, 
birds, automobiles, and geography ). Create your 
own dictionary. 

Softsync, Inc. 

Hangman 

16K RAM. Cassette: $14.95. 

A learning tool to tutor children (ages 6-12 ) in 
spelling. Seven versions of Hangman. Play 
against the computer's five prerecorded libraries 

ters): animals, science, countries of the world, 
states of America, and fruits and vegetables. 
Create your own library of 500 words. 

Z-West 

Hangman 

16K RAM. Cassette: $4.95 plus $1 s&h. 

The computer becomes a very special vocab- 
ulary tutor in this traditional game of Hangman. 
Discover the unknown word before you are 
hanged! 5 levels of play with 5 words in each 
level. 

Golf 

Asia Tsusho Co., Ltd. 

Golf Game 

16K RAM. Cassette: $14. 

A full scale golf simulation game of 18 holes 
by adopting the table of random numbers sys- 
tem. By inputting in sequence CLUB SELECT, 
DIRECTION, STRENGTH, you can enjoy your 
golf game with green scenery varied from time 
to time. 

Biocal Software 

(See Directory of Suppliers for prices.) 
Golf. IK RAM.' 

Get your clubs out and play a few holes. 
Good for judging distances. 



July/August 1983 c SYNC 



USER FRIENDLY SOFTWARE 

for the T1MEX/SINCL AIR 1000 

Data-Manager (DM)* 

Screen prompted data collection sys- 
tem with formula fields and both form 
and spread sheet display 
Finance-Manager (FM)* 

Combines budgeting, record keeping, 
and check reconcilement into one 
operation 
Program-Manager (PM)* 

BASIC and machine code program 
monitor and utility Functions include: 
renumber, copy, delete, search, dump, 
Hex load, Hex Debug, and a condense 
mode that reduces program memory 
size. 

All programs are supplied on cassette with full 
size instructions that are easy to read and easy 
to understand. 16K required 

$14.95 each postage included 
VISA MASTERCARD or check 

TOLL FREE ORDERS 

t -800-543-3000 ask for 

operator #520 item code* 



Al I COMPUTER ASSISTANCE INCORPORATED 

W#%l P0 B0X 3402 C , NC j NNAT | OHIO 45201 / (513) 381-8778 



■.•nmjKo^ rima 



Now you can organize your copies of 

SYNC 



Now your magazines can be a handsome addition to your decor, 
well organized, and easy to find, thanks to these durable li- 
brary-quality cases or binders. They're made of luxury-look 
leatherette over high-quality binder board. And both styles are 
custom-designed for this or any other magazine you save, with 
size, color and imprint selected by the publisher. FREE transfer 
foil included foi dates and volumes. 

^„ CALL 

' A Sj? TOLL-FREE 24 HRS: 800-526-0790 



Magazine binders 




3 for $22.5 

Open-back cases 




ualre!- i 

■ 



nly: 201-540-0445) 



bync 

CN1914, Morristown. NJ 07960 

■ 



~l 








mum$10): 



itur< _ 









I _. 






.J 



CIEVA computer ware 



ZX81 



TS1000 



ENTERTAINMENT PROGRAMS 

SNAKEBITE Eat the snake before it eats you. 

BATTLE Demanding game of military strategy 

that can be played by 1 to 4 players. 

STARSHIP TROJAN Pit your wits against the dangers of 

outer-space and try to save your damaged 
space-craft. 
PRINCESS OF Face the monsters hiding in the 

KRAAL underground and save the Princess. 

STARTRACK Use photon torpedos to kill off the Klingons. 

FUNGALOIDS Save civilization by bombing the ever- 

multiplying fungus. 

CRAZY-CARDS Totally addictive for cheats. 
CUBE Use your computer to solve the mysteries 

of the RubikCube. 

TWO GAMES FOR THE PRICE OF ONE (ONLY $12.95) 
All programs 16K 

MACHINE LANGUAGE PROGRAMS 

ASSEMBLER $16.95 

2 pass assembler written especially for the ZX81/TS 1000 (16K). 
It is simply the best assembler available for those who wish to 
write their own machine code programs. It is designed to run 
alone, or together with the dis-assembler, and/or the de-bug- 
ging program. These provide a system for writing, editing, check 
ing and testing machine code programs that is second to none. 

DIS-ASSEMBLER $16.95 

Allows you to read the ZX81/TS 1000 ROM (16K) with the best 
dis-assembler program available. It is written specifically for 
Sinclair/Timex computers, and unlike some programs modified 
from Intel 8080 dis-assemblers it gives full Z80 Mnemonics. 

DE-BUGGER $16.95 

Makes writing machine code programs easier. Works entirely in 
decimal. Therefore hexadecimal is not needed. (16K) 

PROGSTORE/TOOL-KIT $16.95 

Progstore contains a series of machine-code routines that cre- 
ate 3072 bytes of user space and then transfer into this space 
machine-code routines that allow the transfer of a BASIC pro- 
gram into the user space after running this program allow a 
return to another BASIC program stored conventionally in low 
memory. 

TOOL-KIT 

Progstore toolkit contains four "utility" programs specially 
written to operate from progstore. Having loaded progstore in 
Toolkit can be loaded and then progstored with RAND USR 
32500. Each program can be run by RAND USR 32723. 

HEXLOADER— This program allows machine code programs to 
be rapidly written in hexadecimal. 

HEXLISTER— This program complements HEXLOADER by allow- 
ing machine code programs to be listed in hexadecimal. 

PROGMFRGE $16.95 

Progmerye contains a series of machine-code routines which 
allow BASIC programs to be stored whole or in part. 

Please send check or money order NO CASH' 

New York Residents only add 8' 4 °o Sales Tax. 

SHIPPING AND HANDLING 

Add $1 50 for first item and $ 50 cents for each additional item 

Name 

Address 

City State Zip 

Mail To: CLEVA Computer Ware 

PO Box 2736 

Brooklyn. NY 11202 (212) 875-1207 



GAME CASSETTES 
TIMEX-ZX81 $14.95 EACH 

MONOPOLY" FAMILY GAME FOR 
UP TO 6 PUWERS-AVAILABLE IN 
AMERICAN, SPANISH OR BRITISH 
LANGUAGE VERSIONS. 'WINGED 
AVENGER IBST GOLD SEAL 
SPACE GAME. -SPACE TREK NEW 
RELEASE!! SPACE GAME. TRAD- 
ER JACK' FANTASTIC FUN GAME- 
BUSINESS LOGIC-SOUTH PACIFIC 
LOCAL. -CASINO' INCLUDES PO- 
KER-MACHINE, SUDDEN-DICE, 
FIVECARD AND CHUCK-LUCK. 

TEN GREAT GAMES INCLUDES 
PACMAZE, GOBLER. ASTRO STAR 
DEFENDER, VAMPIRES, SUICIDE, 
MINEFIELD, FROGLER. STARTREK, 
DICTATOR. BOMBER. 

SAVAGE SOFTWARE PO BOX 441 
TITUSVILLE, FL 32780 



PRQGRAMERS 

Every Progrsner has written a 
program swieone else would buy* 

We will package arid promote your 
usable programs and pay you a 
conpetative royalty* 

Send a description of your 
program to our office* The sooner 
you subnit your work* the sooner 
we can prorate it for you ! 



SOPHIA SYSTEMS 

15122 Pheasant Drive 
Surrey, 6*C* Canada, V3R 4X6 



LEARN TO 
PROGRAM 

Text and File Organizers with 

ZX DATA FINDER 

A high capacity information 
storage and retrieval tool for 
16 K Timex and Sinclair Com- 
puters. 

Advanced file input and editing 
routines are thoroughly 
analyzed. 

Comprehensive search and 
display methods are fully 
explained. 

AN ADVANCED COURSE 
IN DATA HANDLING 

Free specifications are 
available, or send $9.95 for 
program listing and tent to: 

THOMAS B. WOODS 

P.O. Box 64, Jefferson, N.H. 03583 



Computronics 

ZX Open 

16K RAM. Cassette: $16.95. 

Simulates golf on 5240 yard, par 71, 18 hole 
course. Select driver, irons, pitching wedge, or 
putter. Holes, slices, or misses the ball. Sand, 
water, or lost in the trees. Up to 4 players. 
Automatic score card. 

Emvee Software 

Mini-Golf 

16K RAM. Listing: $6. 

Play 9 or 1 8 holes against another player or 
the computer. The better your practicing per- 
formance, the better your practicing perfor- 
mance, the more consistent your play will be- 
come. A different course for each round 
played. 

R. Midura 

18 Hole Golf 

16K RAM. Cassette: $10. 

Features a graphics display of each hole, 
animated ball, 3 types of hazards, 5 player 
capability, and final score card display. Hazards 
include bunkers, water traps, and trees. The 
display of each hole lists hole number, par, 
current shot, current score, and name of player. 
9 different courses available. 

Minigolf 

16K RAM. Cassette: $10. 

Graphics display and random creation of each 
of the 1 8 holes ; random height of elevated tee ; 3 
types of variable size hazards: animated ball: 
splash effect: final score report. Also displays 
hole number, hole par. shot number, and current 
score. Distance between tee and hole determines 
par. Flashing messages for misses and hole in 
one's. Can play either same course or a new 
random course. 9 levels of difficulty. 

Supplements for 18 Hole Golf 
16K RAM. Cassette: $10. 

Courses 4, 5, 6 on one cassette; 7, 8, 9 on one 
cassette. Courses 8 and 9 feature unlabeled 
graphics terrain items and more complex holes. 
Courses 8 and 9 offer more terrain items per 
hole and are recommended for advanced 
players. 

Mind ware Inc. 

From Eagle Sales 
Graphic Golf 
16K RAM. Cassette: $9.95 plus s&h. 

A full 18 hole, championship golf course. 
You face a brand new set of hazards each time 
you tee up: trees, bunkers, and gusts of wind. 
Make a choice of club (wood, iron, putter) and 
strength of choice. You also aim the shot. We 
do not promise that you will take the British 
Open, but you will test your skill and judgment. 
By Silversoft. 

Sean Wilson 

Golf 

16K RAM. Cassette: $10. 

Play golf with a full view of the course; nine 
hole course; close up of green for your putt. 
Superb graphics. For one or two players. *m 



EZ Assembler and Editor 

only $4.95 ppd. 

Completely in BASIC. Enter it yourself 
using the source listing supplied. 
\ccompanying documentation is an 
excellent tutorial suitable for schools 
or self instruction. The construction 
of the EZ Assembler and Editor is 
explained for those who would like to 
know how it's done, and to make it 
easy to modify or enhance. 16K RAM! 
BASIC program oniv,on cassette $9.95 
Cassette & documentation $14.90 
Eugene Zweig 

P.O. Box 1022, Pearl River, NY 10965 



MONSTER! 

AWESOME GRAPHICS ! EXCITING 3D GAMES, 
BUSINESS SOFTWARE, PROGRAMING AIDS. 
WE ONLY STOCK THE FrNEST IN SOFTWARE 
FOR THE TIMEX TS1O00, SEND SASE WITH 
THIS AD AND RECIEVE A FREE GRAPHIC PRO- 
GRAM AND A COMPLETE LIST. 



ZX 



DATA 



16783 BEACH BLVD. HUNTINGTON BEACH, CA 926 V7 



CURRY COMPUTER 

ZX81 and T/S 1000 

Software & Hardware 

Write for FREE Catalog 

Over 60 Programs/Keyboards/Rampacks 

DEALER INQUIRIES WELCOME 

5344 W. Banff Ln./Glendale, AZ 85306 

1-602-978-2902 



Need a good game to play or pro- 
gram? Circle Chess board with in- 
structions $5.00. Send your record- 
ed Circle Chess games and pro- 
grams for publication in Circle 
Chess Journal, Box 63, Des 
Plaines, IL 60017. 



I am selling Software for very cheap 
prices: Call or write for free details: 
914-969-7750 or 

Robert Cannon 

309 N. B'way 

Yonkers.N.Y. 10701 

Jerry and Neil nonbelievers 




ARE YOU FOR SALE? 

If you have marketable software let us hear from 
you. If it meets our quality standards we could 
make you a cash offer or suggest a royalty 
agreement. If not we'll be honest and explain 
why. Send for our SOFTWARE AUTHORS IN- 
FORMATION GUIDE It could be the 
beginning 
ROBOTEC. INC..PO.Box55.Rossford.OH 43460 



114 



July/August 1983 c SYNC 



SOUND EFFECTS • MUSIC 
& two JOYSTICK - I/O PORTS 

The ARCADE MASTER A&T $64.95 

Plug-in Module for ZX81 and TS1OO0 

Now you ran create complex arcade tjualiu sound effects, write melodies m 3 part har 
mony, & control tht- action with one or two Atari compatible joysticks (not included) 



•3 tone ge nerator s 8 octive range 

• i channel mixer, amplitude 
controller, and envelope generatoi 

•Noise generatoi 

• Intfrnal speaker, Milium- control, and 
amiiu output |ack 

• Requirei no additional power suppl) 



•Complete instruction manual and 

examples 
•Can !>«■ used with printer, l f, k 

rampak, atid most otrwr mnclulrs 

• 2 Independent, TTL compatible I () 

ports tan !*• used as general purpose 
input output, or with joysticks 



SPEECH MODULE The PARROT™ ( b>R i s t> $89.95 

Generates 64 Allophones (Speech - Sounds) which you combine to 
create any words, phrases, sentences, or sound effects you wish. 

•Complete instructions & examples *Can rx> used with other modules 

•Speaker jack (drives 4 or 8 ohm •Compact, reliable, thorougjhl) tested 

and sale 



2 AMP POWER SUPPLY 



ZX80/81 • TIMEX 1000 • MICROACE 



As you expand your system, you'l 
This suppl) has it 1 



need more power to run it. 

SPS-2A - POWER SUPPLY - $19.95 



MULTIPLE OUTLET STRIP «.ih Du.it m 2 STAGE TRANSIENT ABSORBER 

PROTECTS YOUR COMPUTER SYSTEM FROM DANGEROUS VOLTAGE SPIKES 
Absorbes transients and surges such as those produced h\ lightning, switching surges 
and noise spikes. 4 protected A.C. outlets, 15 A.C.B.. power switch & pilot light 
6 foot cord TA4- TRANSIENT ABSORBER- $29 95 

MULTIPLE OUTLET STRIP organize your computer work station $19 95 

Four grounded A.C. outlets, 15 amp C.B., power switch & pilot light. 6 ft. cord. 




Send check or money order to: 

HURRICANE ELECTRONICS 

P.O. BOX 237 • LANSING. IL 60438 

include $2.50 thipping handling per order 
Illinois residents add 6 '7 fax 



Haymarket Software 





QNTY 




teach 


Total 








FOR ADULTS ONLY 


19.95 










RING OF THE GODDESS pt, 1 


12.95 


m 








RING OF THE GODDESS pt.2 


12.95 


. 








FLIP-FLOP 


10.95 


. 








ZX-BLACK HOLE 


10.95 


. 


o> 


o 

o 

o 




ZX-CGNCENTRATION 


8.95 


. 




HAYMARKET HANGMAN 


9.95 


. 


< 




MAZE-O-RAMA 


9.95 


, 




ROAD RACER 


9.95 


, 


<r> 


1 




SPACE TREASURES 


9.95 




p\ 


c/9 




PATTERNS/TOWERS 


9.95 


• 




f- 




MAZE-6-TRIASURE 


9.95 


. 




s, 










N 












X 

| 


oO 




SUB TOTAL 






X 




FLORIDA RES. + 5* TAX 






u» 




SHIPPING AND HANDLING 




1.50 


N 




TOTAL ENCLOSED 






^ 


NAME 
ADDR 
CITY 
Send 






ESS 


oO 


/STATE Zip 


' 


in 


rjcheck or Qinoney order to: 

/&SS, HAYMARKET SOFTWARE 
f/y|\ P.O. BOX 14026 
WjwSJ Jacksonville, Florida 

If our tape fails to load for anj 
reason, we will replace it free!* 


1 

O 
O 

o 




TS 1000 m /ZX81 m OWNERS: Cl-QC 

"TOUCH TYPE" FOR JUST *0 

• Improve programming and game playing, too! 

• Easy to install - no wiring or soldering required 

• Clear Vinyl with key-shaped openings and 
adhesive backing. 

TYPEX/81™ Keyboard 
$5.95 + $1.50 P&H 

Order by mail or phone. 

216/234-2662 • VISA & MASTERCARD welcome. 
GANHART/EARTHings 

115 N. Rocky River Dr. dealer,distributor 

Berea, OH 44017 inquiries invited 



DDDDDDDDDD 

DDnnDDDnnn 
DDDDnnnnnD 
□□□□□□□□□□ 



$l0f 



L«** 




Business/ Professional Applications 
for Timex/Sinclair users. 



Busyness is rhe only publicarion 
geored ro professional & business applica- 
tions for Timex/Sinclair users. Six rimes 
yearly Busyness presents Feature articles. 
New Products Information, Resource List- 
ings . . . and more 



Enclosed is my check for $12.00 to cover a one year 
subscription. Moke check payable to Busyness 

Nome 



Address 



.Zip 



City (j Srate 

Busyness • P. O. Dox 421 773# S. F. . CA 94101 



INTEGRATED 
DATA SYSTEMS 



Audiograph Chirper 
Bi-PackZONX-81 
Kayde16KRAM 
Kayde 64K RAM 
Kayde Graphics Board 
Q-SAVE 



$ 13.20 
49.28 
51.28 
about 112.00 
58.64 
42.07 



RIST Parrot (speech module) 90.30 

Timeworks, Softsync, IPS and 

others. 

Graphicornp educational programs 

on many subjects 1 1 .92 

Postage $1.50/order. CDN prices on 
request. FREE catalogue. Mail 
cheques to 1 1 Brighton Av Toronto 
M4M 1P3 or phone VISA to 
416-466-5571. 1-4wkdeliv. 
For U.S. orders only. 



[TO JPUTW ENGINEERING 5EM71K5 

The Jarrett Company 

P.O. BOX 1222 

SHOW LOW. ARIZONA 85901 

THE MOST COMPLETE SOURCE OF 

SERVICES FOR THE COMPUTER 

ENTREPRENEUR 

Software Duplication on Cassette. 

Marketing/Publication/Packaging/ 

Manufacture and Prototyping. 

Write for Free Brochure! 

ZX-80 8K ROM USERS 

Completely expand your ZX-80 with 8K 
Rom to a ZX-81 with full use of Fast and Slow. 
Smooth flicker free performance! 

rnmntofo Kit <^9 W A $9 Sf) nn«;tAnp ft 

handling; PCB only $19.95 & $1.25 
The Expandable ZX-80 and ZX-81 
TS-1000 / Microace Too 

A book of hardware projects that you can 
build yourself, from memory expansion to 
speech synthesis. Only $9.95 & $1 .25 p&h. 
(Dealers Inquiries Invited) 



FFJEt 



Get a high quality 38 inn. computer 

grade cassette FREE with every 

software selection purchased 

DISCOUNT PRICES 



*/> 



-TROCCER 
PINBALL 
GULP 
LABYRINTH 

GRinns tairy trails 

Vil CAM 
-ORGANIZER 
-CHECKBOOK MANAGER 



•17.95 
•12.95 

♦15.95 
♦15.95 
• 8.95 
•18.95 
♦15.95 
♦14.95 



HUNDREDS MORE SEND FOR OUR TREE CATALOG 

HARDUARE DISCOUNTS » ■ 

-PAHASONIC SLIMLINE TAPE RECORDER $29.95 
TlttEX/SINCLAlR 1816 < 1 6K RAM) »42. 95 
-ZENITH GREEHSCREEN < I?" ZVN/121 >• *99.95 



SINCLAIR SUPPLY SHACK 



FOR CATALOG SEND TO: 

SINCLAIR SUPPLY SHACK 
22626 WOOLS EY DR. 

HHV1. Ml. 4hm->m 



Just for Fun, continued... 

impressive but require more programming 
expertise, as anyone who has tried to 
combine the relationships of PLOT, 
PRINT AT, or TAB can testify. 




The program cannot produce a com- 
plete screen of full bars with only IK, but 
if the data is not 50 each time, the pro- 
gram can be used with only IK. To get 
the most out the program, the prompts 
can be shortened (or even omitted) and 
line 10 can be deleted. Users with 2K 
need not worry about memory because 
the program and display is well under 2K. 



Isosceles Triangle 

Michael W. Schultz 

This program will draw an isosceles 
triangle, which is any triangle with two 
equal sides and two equal angles. This is 
done by drawing the base of the triangle 
(lines 20-50) and then two ragged lines 
starting at a fixed poini and ending ai 
each end of the base (lines 60-100). These 




lines are the equal ones and they form 
two equal angles at the base. 

Enter the program in Listing 1. Hit RUN 
and ENTER in the SLOW or FAST mode. 
To draw an inverted isosceles triangle 
make the changes given in Listing 2. 



Listing 1 . _ 



10 REM "ISOSCELES TRIRNGLE" 

15 REM DRflU THE BR3E 

30 FOR X = 10 TO 50 

4-0 PLOT X,10 

50 NEXT X 

55 REM DRRU ERCM SIDE TOGETHER 

50 FOR Y=30 TO 10 STEP -1 

80 PLOT Y,Y 

90 PLOT SV?- 

100 NEXT Y 



Listing 2. 



40 PLOT X.. 3© 

60 FOR Y = I0 TO 30 

30 PLOT Y+20..Y 

90 PLOT Y..Y-40 



Mandalas 

Randy Adams 

Type in this short program. It should 
be RUN in FAST mode. Input values 
such as 8, 10, 11, 13, 14, 16, 22, 26, 28, 31, 
34, 35, 38, 44, 46, 47, 50, etc. Any value 
from 1 to 100 will work, but not all of 
them will produce symmetrical figures. 
Try numbers 31, 32, 35, 38, and 26. 

Randv Adams. 262 Edgrace Lane, Santa Cruz. 
CA 95062. 



S INPUT Z 

7 CLS 

10 FOR B=l TO 20 

15 FOR Nsl TO 2*Z 

20 PLOT 31-B*COS iN/Z*PI) , 2i -B 

'SIN (N/2tPI) 

25 NEXT N 

30 NEXT E 




Name Program 

Jody Koenig 

This program demonstrates a cute trick 
which can be turned into a very useful 
and effective teaching program with a 
few additional lines. To use the program, 
simply type in the program in Listing 1, 
put your computer into SLOW mode, and 
press RUN and ENTER. Add the lines in 
Listing 2 for a spelling aid. With the 
addition, you can input a word and go 
through it one letter at a time by pressing 
ENTER. The inverse letter makes it easy 

Continued on pa%e 118. 



116 



July/August 1983 ' SYNC 




TIMEX 1000 ZX-B1 (80) 

□ 8-Port 10 

Interfaces up to eight 
one- byte ports 
Accepts 16K RAM 
10 $89 

□ ADDA 

2-channels A/O, 2-D/A 
Computer sensing and 
control of (analog) 
electrical devices (0-5V) 
ADDA $89 

□ Beeper (Clock /Switch) 

Programmable frequency tone generator, 
clock (milliseconds to years) . . . 
BCS $89 

Each board comes with educational docu- 
mentation, applications, 
and applications programs m 

(1K RAM). $5 handling IWIICf O 

charge on all orders. 



ORDER 
TOLL FREE: 

800-227-1617 

operator 641 
(CA, 800-772-3545 
operator 641 ) 

Box 1140 

2000 Center Street 

Berkeley, CA 94704 

developments 



MICROSYSTEMS SPECIALISTS, INC. 

Announces 
The Latest Breakthrough 
inZX81/TS1000 Software 

ySS™-Backup $14.95 

• Make backup cassettes of your favorite 
programs! 

• Requires only one tape recorder! 

• Makes multiple copies! 

• Simple to use! 

AiSS™-Pilot $29.95 

• Excellent introductory language for children 
and beginners! 

• Easy to use— no prior computer experience 
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• Pilot features one character commands! 

• Includes line editor, tutorial and sample pro- 
grams! 

Call TOLL FREE: 1-800-227-1617 Ext. 157 

in California: 1-800-772-3545 Ext. 157 

OR send check or money order to: 

Microsystems Specialists, Inc. 
P.O. Box 733, Adelphi, Md. 20783 

Add $2.00 shipping and handling for first cassette, 
$1.00 each additional item. Maryland residents add 
5% sales tax. Overseas orders add $3.00. 




^ % ZX81 
KEY-TOP 
SYMBOLS IN 
3 COLORS 

The Crowning Touch for 
Your Converted Keyboard 

Original ZX81 symbols in Red, Blue and Black on White 
background, covered with 7.5 mils of clear vinyl, and backed with 
a tough, pressure-sensitive adhesive. 

The vinyl overlay is extremely durable, with just enough flexibility 
to keep the original curve in the key top. When trimmed and 
sealed per instructions, the edges disappear; the keys look and 
feel like they were custom-made for your computer. (Caps may 
be painted any color.) 

Includes SHIFT LOCK, an extra FUNCTION/ENTER, and two 
SHIFT keys in larger, sizes, in case you choose to use over-size 
pads for these functions 

Complete instructions and diagrams for converting inexpensive 
keyboards to customized ZX8 1 TS 1 000 consoles. 



Money back guarantee, of course. 



$9.95 



MULE Electronics 

Dept. 310A 

444 Lincoln Bl. Venice, Ca. 90291 

Please add $1.50 for shipping, and include 6% sales tax in California. 



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• CONTROL CENTER-FOR T, S 1000. ZX-81-NO CABLE 
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• NUCLEAR REACTOR SIMULATOR: NOT A GAME 

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GRAPHICS INC SCHEMATIC VIEW OF PLANT FOR 
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• AB ENGINEERING, 11896 CLAIR. HARTLAND. Ml 
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W/REOUIREMENTS 

• COMING SYS TO MAKE YOUR RAM CRASH-PROOF 



§ FREE JOURNAL 

2 SINCLAIR owners send S.A.S.E. to 
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INDEXING AND MICROFORM 
AVAILABLE 

This magazine is indexed in THE MAGAZINE INDEX 
available from Information Access Corporation. 
404 Sixth Avenue, Menlo Park, California, and in 
microform from Xerox University Microfilms. Ann 
Arbor. Michigan and Bell and Howell, Micro Photo 
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ELECTRONIC CIRCUIT DESIGN 

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451 Center St. 

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$7 95 ZX-BATTLESHtP GAME $7 95 

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IT IS LIKE THE BOARD GAME. BUT ON YOUR TlMEX-SWCLAlR COMPUTER 

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ATTN i ZX81 & TS1000 Game players J 
Sjrnole Illustrated Atari Joystick 
Instructions. You only need a joy 
stick, no extra parts! Send only: 
453.50 to: EASY INSTRUCTION P.O. 
Box 23582 Milw.,WI. 53223 HURRY I I 




to see how a word is spelled, and it is 
especially effective with young children. 
Listing I 

13 PRINT "INPUT YOUR NflHE ' 
^0 INPUT fl$ 

A.% LET fi»(l)=CHR» ((CODE H$. 
+ 12B) 

4-5 PRINT hT 1U,5,R$ 

50 FOR F=2 TO LEN R* __ m 

60 LET fl$lF-l)=CHR$ ((COPE R$ 
c -11 ) -ISO J 

70 LET R$(FJ=CHR$ ((CODE R$(^ 
-12831 

30 PRINT RT 10, 5, R* 



313 NEXT F 
100 LET RflLEN R*> 
** (LEN R*> I -180) 
110 GOTO 35 



:CHR$ ( (C 



35 PRINT RT 

4- a INPUT U* 

75 INPUT U$ 

105 INPUT U* 



Listing 2. _ 
10,5; R$ 



Jody Koenig, 1005 Mechanic Street, Decorah. 1A 
52101. H 



CHirchoidz Report 



A Machine Code Graphics Line-Drawing 

Subroutine, 2:6. 

Listing 3: Delete one INC HL at address 
40A1H 

Listing 6: Insert equals signs between 
the letters and numbers in the LET state- 
ments. 

Making Backups for Machine Language 
Tapes, 3:1. 

Section 2. Copying with PEEK and 
POKE. 

The second paragraph should begin: 
PRINT PEEK 16388+256*PRINT PEEK 
16389 . . . 

In the third paragraph the SAVE dir- 
ections should read: To SAVE, enter 
GOTO 370 .. . 

A Small Business Payroll Program, 3:2. 

Add to the menu routines the marital 
status options: 1— single; 2— married; 
3— head of household. 

Math Support for Your ZX81, 3:2. 

The alternate lines referred to in the 
last paragraph are: 
870 INPUT AS 

880 IF A$="" THEN GOTO 910 
890 INPUT B$ 
900 GOTO 800 
910 CLS 
920 RUN 

To superimpose graphs, add: 
810 FOR X=-W TO W 
830 INPUT Y 

To improve response to the menu: 
40 LET A=VAL INKEY$*150 
50 CLS 
60 GOTO A 

Minotaur, 3:2. 

Enter the list of variables in the im- 
mediate mode (i.e., without line numbers 
e.g., LET A=l). A through 1=1; J = 512 
K= 16396; L=33; O=0; P=1;Q=2; R=3 
S=5; T=20; U=31; V=128. Check by 



pressing PRINT (variable letter) and 
ENTER. Do not use RUN or CLEAR since 
these wipe out the variables. 

To start type GOTO P; when the cursor 
appears, enter the density (0-1; try .35). 
To restart at the same density, type GOTO 
T. To set up the same maze again, press 
BREAK (except when entering density), 
type in RAND n (n = a number from 1 to 
16535). Use the same number to repeat 
the maze. After the RAND command, type 
GOTO T to start. At density .35, RAND 
19, RAND 20, and RAND 40 produce 
challenging mazes. The author would ap- 
preciate reports of "good numbers"; be 
sure to include the density setting. 



Kneeing Your Strengths. 3:2. 

The author comments: 

One of your astute readers in translating 
the program into TRS-80 Basic caught an 
unnecessary negative and a flow error 
which gives spurious results when attempt- 
ing to RECALCulate new section or ma- 
terial sections. Make the following cor- 
rections: 

Changes: 
1545 IF N=4 THEN GOTO 2050 
2140 LET S2=(W*L)/6*Z) 
1545 corrects the flow and 2140 eliminates 
the unnecessary negative. 

Add: 
3005 IF N=4 THEN GOTO 3020 
3035 IF N=4 THEN GOTO 3050 
3075 IF N=4 THEN GOTO 3090 
These skip the W, L, and XI inputs. 

Eliminating the printout (line 1622) will 
save screen space. 

To eliminate unnecessary, screen con- 
suming decimal places change: 
3505 PRINT ". . . PT.)= H ; INT 
S2;"#PSr 

Some additional output I have found 
helpful: 

3515 PRINT "STRESS= M ; INT (100/(S 
/32));*WPCT. OF YIELD" H 



118 



J uly/ August 1983 e SYNC 






Here's the best from Sync, 
the exciting magazine devoted 
to Sinclairs! 

The Best of Sync is a collection of more than 80 of the 
most valuable articles, programs, tutorials and re- 
views that appeared in Volume One of Sync, the magazine 
for Timex Sinclair and Sinclair owners. 

This information-packed book is a vital resource for 
anyone who'd like to get more work (and more fun!) from 
a Timex Sinclair 1000, a Sinclair ZX81 or ZX80, or a 
MicroAce computer. Topics covered include: 

• Games 

• Mathematical applications 

• Graphics techniques 

• Software programming 
Translation 

Machine language hardware 
Resource listings 

• Product reviews 

• Complete glossary 

In The Best of Sync you'll find game programs like 
"Forest Treasure" and "Motorcycle Race Game"... hard- 
ware plans for a "Key Click Generator" and a "Parallel 
Interface". . .programming features on "Handling Charac- 
ter Strings in the ZX80," "Converting from Other BASICs" 
and "An Introduction to Machine 
Code." And that's just a small 
sample. 

These ultrapractical fea- 
tures appeared in issues of Sync 
that are now out of print and 
nearly impossible to find. But 
you can still make use of , 

the important information, 
techniques and programs 
they contain- by ordering 
The Best of Sync today! 

Also available at your local 

bookstore or computer store. 8 V x 11 ", softcover. 




For faster service, PHONE TOLL FREE: 800-631 -8112 
(In NJ only: 201-540-0445) 



CREATIVE COMPUTING PRESS 

Dept NE5f^ 39 East Hanover Avenue, Morris Plains, NJ 07950 
Please send me 



The Best of Sync, Volume One, at $9.95* plus 

$2.00 postage and handling each. Outside USA add $3.00 per order -6M 

□ PAYMENT ENCLOSED $_ 



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State add applicable sales tax. 
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.^^■■pj^ttwybiiiiiiiipia 

2-BIT™ SOFTWARE, P.O. Box 2036 

Dept. SN2, Del Mar, CA 92014 

(619)481-3629 



DEALER INQUIRIES INVITED 



PLUG IN SOFTWARE 
PROGRAMMERS TOOLKIT and on PLUG IK CARTRIDGE $29.96 
GRAPHICS ROUTINES 16K-64K COMPATIBLE 

A cartridge that plugs between your ZX/TS and your RAM PACK, printer, etc. The 
toolkit portion contains commands that wilt RENUMBER, DELETE, GENERATE, 
SHORTEN, by DUMP is in FREE, SEARCH AND REPLACE E Stnp in. The graphics 
commands include: UPSCROLL, DOWNSCROLL, LEFTSCROLL, RIGHT 
SCROLL, INVERT SCREEN, FILL SCREEN, turn BACKGROUND. DEFINE. The 
cartridge uses the normally unused 1 2K to 1 6K block of memory so that it uses none 
of your valuable BASLIC programming area. ADD $2.00 POSTAGE & HANDLING 
CASSETTE SOFTWARE 
MORLOC CASTLE: 16K Ram ZX81/TS 1000 $14.95 

Similar in style to DRY GULCH. MORLOC CASTLE is. however, written in machine 
language to provide much faster response. Estimated time to solve is 30-50 hours 
MORLOC CASTLE provides over 200 words of vocabulary, is SAVEable in prog- 
ress and uses every last BYTE of RAM. VERY DIFFICULT (HINT SHEET 
AVAILABLE) 
DRY GULCH: 16K Ram ZX8/TS1000 $9.95 

DRY GULCH is an interactive adventure where the user/player types in short 
English phrases such as Go North. Take the Hammer, Saw the Iron Bars, etc. to 
explore a deserted old west ghost town and search for treasure It is wntten in BAS IC 
and is saveabte in progress. Estimated time to solve is 10-12 hours. TRY THIS 
ADVENTURE FIRST. 
PROGRAMMERS TOOLKIT and 16K RAM ZX/TS $12.95 
GRAPHICS ROUTINES 

The same program as supplied don plug-in cartridge (see other side) except this 
cassette loaded program needs RAM in the 12K to 16K block (such as available 
from HUNTER PRODUCTS or 64K RAM packs). 
KITS & PLANS 
I/O ports and EPROM programmer for ZX81/TS1000 (plana) $5.00 

Schematic documentation , and software listing to build a 24 line I/O port then use it 
to program: 2716, 2732, 2732A, 2764 EPROMS 
EPROM CARTRIDGE KIT $1 6.95 

Kit includes all parts necessary to build a plug in cartridge that will accept 2716, 
2732, or 2764 EPROMS. Board may be memory mapped in 4K or 8K increments 
anywhere from 0- 1 6K. The board accepts one EPROM and the memory mapping is 
jumper selectable. EPROM not supplied. DEALER INQUIRIES INVITED AND 
QUANTITY DISCOUNTS ARE AVAILABLE. 

ALL PRICES INCLUDE POSTAGE & HANDLING EXCEPT WHERE NOTED (NEW 
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UPSTATE LABS 

27 ELVIRA ST. 

ROCHESTER, N.Y. 14606 




Index to Advertisers 



Aardvark 33 

AB Engineering 1 18 

Aerco 46 

A 4- Actn^ialM .... 1 08 

Apropos Technology 1 1 

Atto Software 1 1 1 

Audiograph 109 

B. Dalton Bookseller 38 

Eric Beckett .... 118 

Bob Berch 37 

Bingel Robotics 109 

Bi-Pak Ill 

Basco (Blase Sanzone) 112 

Bonnie & Clyde Software 79 

Brainchild Computer Works 71 

Bronze Star Software 74 

Business Management Specialist 45 

Busyness Magazine 115 

Byte Back 99 

Bytesize Products ... Ill 

Robert Cannon. 114 

Centronics 17 

Circle Chess ! 14 

Cleva Computer Ware .113 

Cobra Tech Ltd 41 

Computer Assistance Inc 113 

Computer Continuum 78 

Computer Engineering Services 1 16 

The Computer Trader 85 

Computer- Wear Software 14 

Compusoft 75 

Compuwiz Software 112 

Cottage Technology 102 

C.R.C. Software 118 

C-20 Magazine 104 

Curry Computer 1 14 

Bob Darin (formerly Bob's) 118 

Data Assette Cover 2 

Datacon 83 

Daydesign 114 

Discount Software 85 

Dennis A. Donovan 112 

Down East Computers 103 

Eagle Sales 1 

E. Arthur Brown & Co 105 

E. Arthur Brown & Co 106 

Expense Cutter Products 95 



E-Z Key 67 

Filesixty 29 

The Fourth Design 105 

The Forth Dimension 64 

Fiicuulj C^putcr 118 

Fuller Micro .47 

Ganhart 1 15 

GCM Electronics. 65 

The Golden Stair 109 

Graphicomp 10 

P. Hargrave. 107 

Haymarket Software 1 15 

Heath Computer Services 28 

Horizon Simulations 105 

Hunter 96 

Hurricane Electronics 1 15 

IMS Enterprises 110 

Independence Research 84 

Integrated Data Systems 1 16 

Intercomputer 8-9 

Jameco 53 

Kopak Creations. 106 

KVC. Inc 20-21 

L & G Enterprises 1 10 

Leading Edge .Cover 4 

Maranatha 54 

Markel Software 1 12 

MAV Microproducts 108 

Melbourne House Software 55 

Memotech Corp 26-27 

Micro Design Concepts 57 

Micro Developments ... 117 

Micro Sync. 22 

Microsystems Specialists, Inc 1 17 

Mopsy 107 

Mule Electronics 1 17 

Oasis 51 

Orbytc Cover 3 

Panda Software 16 

Peak 24 



People's Computer Supply.. 
PteasanTrecs 



117 

103 

Polymath 82 

Que Computer Books 6 

Ramex International 51 

RAM Products 82 



Research Applications Products 14 

R.I.ST 57 

Robotec 7 

Robotec 114 

Savage Software 1 14 

Simplex Software ... SI 

Sinclair Place 63 

Sinclair Supply Shack 1 16 

Sinclair Users' Network 112 

Singh Computer Supplies 1 18 

Sinware 101 

Siriusware 107 

Joe Smiley . 112 

Softsync ... 59 

Solutions 50 

Sophia Systems 114, 106 

Spyder Electronics 84 

Strategem Cybernetics Inc 88 

Stream Computer,... 79 

Sunflower Systems 64 

Suntronics 94 

Syber Inc 108 

Sybex 4 

Sync Master 105 

Sync Ware Company 90 

Synergies Unlimited 57 

Synergistic Design 91 

Tapemasters 36 

2-Bit Software 120 

THM 108 

Timeworks, Inc 35 

Toco Technology 109 

Troiano Software 1 12 

21st Century 2 

UAS (Utility) Auditing Services 112 

Ultimate Blackwood 72 

Upstate Labs ... 120 

User Friendly Research ... 1 1 1 

RE. Woish H8 

Tom Woods 114 

York- 10 39 

Zebra Systems 13, 15 

Zor Khan Ind 57 

Z-Tron Int'i 112 

Eugene Zweig .114 

ZX Data 114 



J 



Education, Business, Entertainment . . . 





Exi*> 



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Seven New Programs 
For the Small Business 

• Customer Credit File 

. f^n^ral I edq er - 

• Ecucu Diary 

• Exec Address & Phone File 

• Accounts Payable 

. • Accounts Receivable 

• Inventory 



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Timex Sinclair 1000 • Sinclair ZX81 



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Meet the Bananarthe very 
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